Hawaii and USAPI Climate Summary

This webpage serves as a digital version of the quarterly "Hawaii and US Pacific Islands Region Climate Impacts and Outlook". The quarterly outlook draws on the PEAC Climate Center's "Pacific ENSO Update" quarterly newsletter and other sources to bring together seasonal predictions and projections alongside information on recent impacts of weather and climate events in a concise and accessible format. The top four tabs (below) mirror the content that can be found in the current outlook.

This webpage also provides access to information used to develop the quarterly outlook in the form of a “dashboard” that aggregates climate variability-related content via links to products and information from a mix of primarily US agencies, institutions, and organizations.

Climate Impacts and Outlook

Hawaii and U.S. Pacific Islands Region
1st Quarter 2024

Significant Events and Impacts for Previous Quarter by Locale

pacific overlook

Highlights for Hawaii and the U.S. Affiliated Pacific Islands

Significant Events and Impacts for Previous Quarter by Sector

The U.S. Coast Guard Cutter, Oliver Henry (WPC 1140), arriving (2/1/24) at Dekhitik Harbor in Pohnpei, FSM as part of an international relief effort delivering essential supplies and equipment to drought-affected islands in the Federated States of Micronesia. Source: U.S. Coast Guard News.

Key officials, including Governor Joseph, visiting drought- stricken Pingelap Atoll (2/17/24) where critical relief supplies were delivered to help meet local water needs. Source: Office of the Governor, Pohnpei State, FSM.

Large swells/high surf (1/22-23) caused coastal flooding and erosion in Faleāsao Village on the island of Ta’u in the Manuʻa Islands, American Samoa. Source: FB Manu'atele Community Worldwide; NWS Pago.

Flooded runway and debris at the Woja Island Airport, Ailinglaplap Atoll, RMI (above left). Storm surge damage to infrastructure in Roi-Namur, Kwajalein, RMI (above right). Source: Marshall Islands Journal; U.S. Army.

Exposed coral reef during an extreme low tide, coupled with low sea levels, event near the village of Fagaʻalu, Tutuila Island, American Samoa. Source: Eric Brown, National Park Service.

Time-series graphs depicting satellite-based sea surface temperatures, and associated coral bleaching alert levels (red, maroon) for the Northern Line Islands (includes Palmyra Atoll) in the central Pacific Ocean for 2023-24. Areas in maroon indicate bleaching Alert Level 2. NOAA Coral Reef Watch.

Water Resources– On 1/12/24, a drought state of emergency was declared by the Pohnpei Governor Stevenson A. Joseph. On 2/17/24, Governor Joseph visited Pingelap Atoll as part of a delegation to assess the drought conditions (water supply shortage) and discuss the ongoing collaborative mitigation efforts. As part of the international drought relief effort, the governments of the United States and Australia joined in the effort delivering much-needed fresh water, filtration units, and other relief supplies to affected islands in Pohnpei, Chuuk, and Yap states. In Majuro (RMI), reservoir storage reached 71% of total capacity (36,000,000 gallons) on 2/29/24.

Facilities and Infrastructure – In late January, a powerful storm system (1/17/24) in the far northern Pacific generated a very long- period northerly swell that propagated across the western tropical Pacific impacting areas of Micronesia (FSM, RMI) on 1/20/24 and south of the equator in American Samoa. Powerful waves associated with the swell caused significant flooding, evacuations, and damage to homes and infrastructure. Moreover, U.S. military installations, most notably Roi-Namur (below) in the northern sector of Kwajalein Atoll (RMI), were impacted during the event. Other islands affected included Ailinglaplap Atoll and Arno Atoll (RMI) as well as areas of FSM including eastern Yap, Pohnpei, and Kosrae states. On 2/22/24, the long-period swell reached American Samoa producing damaging waves (15-20 feet), which caused considerable damage in low-lying villages on the northern shores of American Samoa (Tutuila, Olosega, and Ta’u islands) including localized flooding and scattering ocean debris (bottom left), according to the NWS Pago Pago.

Numerous low-pressure systems, associated with the South Pacific Convergence Zone, brought periods of very heavy rainfall accumulations to Tutuila, American Samoa during the DJF period. Local storm-related impacts included widespread flooding, damage to homes, debris on roadways, power outages, and disruptions to broadband and telecommunications services, according to reports from the National Weather Service (NWS) Pago Pago.

Numerous landslides were reported in Tutuila, American Samoa including in the villages of Āmanave, Poloa, ʻAoa, Asili, Auto, and Āmouli.

Heat – The ongoing El Niño event brought periods of excessive heat to areas of the southwestern Pacific including Tutuila Island, American Samoa where the observing station at NWS office at the Pago Pago International Airport reached or exceeded 90oF on 19 of 31 days during January 2024. Moreover, the Siufaga Ridge (480 ft.) and Toa Ridge (1285 ft.) observing stations in the National Park of American Samoa recorded maximum temperatures of 98oF and 94oF respectively, on 2/25/24 (based on preliminary data).

Ecosystems – In American Samoa, subaerial exposures of shallow-water coral reefs were observed in Tutuila, including in the villages of Nuʻuuli and Fagaʻalu (top left). These events were driven by a combination of factors including El Niño-related sea level drops in the region and extreme low tide events. In addition, anomalously warm sea surface temperatures were observed in areas of American Samoa around Tutuila Island, Swains Island, and Rose Atoll—reaching Alert Level 1 during January and February 2024, according to the NOAA Coral Reef Watch. In the central Pacific, extensive coral bleaching, mortality, and algal overgrowth were observed in Palmyra Atoll (bottom left), according to field observations from The Nature Conservancy staff and the NOAA Coral Reef Watch.

Observed mass bleaching event in coral reef terraces in Palmyra Atoll, Northern Line Islands (January 2024). Source: Molly Ginther/The Nature Conservancy.

Sea surface temperature (SST) ranking for the western Pacific Ocean for January 2024. Source: ERA5 Reanalysis, B. Brettschneider.

Regional Climate Overview for Previous Quarter

Seasonal sea surface temperature anomaly map for 12/3/23 to 3/2/24 (left) and 90-day seasonal outgoing long-wave radiation (OLR) anomalies for the 12/5/23-3/3/24 period (right). Areas with more clouds/rain are depicted in blue-violet colors while areas with fewer clouds/less rain are depicted in yellow-orange colors. Source: NOAA Physical Sciences Laboratory.

During the DJF period, above-normal sea levels (5-20 cm) were observed across much of the eastern tropical Pacific Ocean and areas north of ~10oN in the northwestern tropical Pacific Ocean, while below-normal sea levels (5-20 cm) were observed in the northwestern tropical Pacific near the equator (south of ~8oN) extending southward to areas around the Solomon Islands and Samoan Islands. By late February, the basin-wide sea level pattern was consistent with having passed the peak of El Niño conditions, according to the University of Hawaii Sea Level Center.

Median precipitation (DJF) was below normal across most of the USAPI, while near-normal totals were observed in Palau and Saipan. For DJF, Airai (Palau) recorded 33.28 in. (98% of normal). In FSM, Yap Proper observed 12.1 in. (55% of normal), Kapingamarangi 43.56 in. (132% of normal, 5th wettest DJF on record), Pohnpei 30.68 in. (76% of normal), Lukunor 22.79 in. (71% of normal), Kosrae 37.53 in. (70% of normal), Chuuk 26.76 in. (90% of normal), and Pingelap recorded its 3rd driest DJF on record. In the Mariana Islands, Saipan observed 9.99 in. (99% of normal) and Guam 9.75 in. (65% of normal). In the RMI, Majuro observed 17.45 in. (62% of normal), while Kwajalein logged 10.45 in. (67% of normal). In American Samoa, precipitation was well above normal (68.08 in.,169% of normal, 4th wettest DJF) at Pago Pago. Across much of the Hawaiian Islands, below-normal rainfall prevailed during the DJF period despite wetter-than- normal conditions observed in Maui during January. For the DJF period, Lihue observed 7.46 in. (67% of normal), Honolulu 3.82 in. (64% of normal), Molokai 7.57 in. (87% of normal), Kahului 6.77 in. (94% of normal), Kailua Kona 3.15 in. (88% of normal), and Hilo 16.6 in. (55% of normal).

In the South Pacific region (east of 135oE), tropical cyclone (TC) activity has been slightly below normal for the 2023-24 season, including 7 named storms with an Accumulated Cyclone Energy (ACE) Index of 43.5 (normal 45.2) by 2/29/24, according to the Colorado State University Tropical Weather & Climate Research Group.

Time-series plot of combined land and ocean surface temperature anomalies (departure from 1910-2000 average) for the month of January between 1970-2024—Hawaiian Region (left). Positive anomalies (red) indicate warmer-than-normal temperatures and negative anomalies (blue) cooler-than-normal temperatures. Source: NOAA Global Surface Temperature Analysis; NOAA NCEI.

Regional Climate Outlook for Next Quarter

Forecast for each of the three possible ENSO categories for the next 8 overlapping 3-month seasons. Blue bars show the chances of La Niña, gray bars the chances for neutral, and red bars the chances for El Niño (left) and ENSO forecast model predictions (right).
Source: NOAA CPC, Columbia University IRI.

According to the latest ENSO prediction model simulations (above right), the majority of models indicate El Niño will persist through March-May 2024 and then transition to ENSO-neutral during April-June 2024 (83% chance). After a brief period of ENSO-neutral conditions, there are increasing odds of a transition to La Niña during the June-August 2024 (62% chance), according to the NOAA CPC (3/14/24).

The NOAA’s Coral Reef Watch four-month coral bleaching heat stress outlook (Mar-Jun 2024) calls for a high probability (90%) of high heat stress (Alert Level 1-2) developing in areas across much of the tropical Pacific Ocean, especially in areas of the central and western tropical Pacific Ocean south of the equator.

NOAA Coral Reef Watch four-month coral bleaching heat stress outlook for Mar-Jun 2024. Red and maroon colors represent areas with a high probability of coral bleaching heat stress Alert Levels 1 & 2.

During the period of March-May (MAM) 2024, below-normal precipitation is forecasted for areas across USAPI, including CNMI, Guam, Palau, FSM, and RMI, while above-normal rainfall is expected in American Samoa. Likewise, below-normal precipitation is expected across the Hawaiian Islands, according to the NOAA Pacific ENSO Applications Climate Center.

During the next three-to-six months, there is a likelihood of below-normal sea level anomalies expanding southward and eastward in the tropical Pacific. Above-normal sea levels are likely to return in parts of the northwestern Pacific, such as around Guam, according to the University of Hawaii Sea Level Center.

Information in the dashboard is grouped first by climate variable and/or impact and then by time frame. Click on any tab in the dashboard, it will expand to show an associated selection of panes. (Click again and it will collapse). Click on any figure in a pane to view a full-sized version, and click again to reduce it. Click on the “?” button to view the figure caption. Note that figures are automatically updated as often as the original providers post them on their respective websites (the update frequency is included in the caption). This means, the figures in the print version of the outlook may not be fully consistent with those found here. Click on the source URL to go to the site where the figure originated and find additional data and information.


Temperature & Precipitation


Latest Week of Global Rainfall

source: http://pmm.nasa.gov/TRMM/realtime-3hr-7day-rainfall

Current Total Precipitable Water

source: http://tropic.ssec.wisc.edu/real-time/mimic-tpw/wpac/main.html

NCEP Reanalysis Model - Air Temperature (Surface)

source: https://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.html

NCEP Reanalysis Model - Precipitable Water (Surface)

source: https://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.html

NCEP Reanalysis Model - Air Temperature Anomaly (Surface)

source: https://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.html

NCEP Reanalysis Model - Precipitable Water Anomaly (Surface)

source: https://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.html

NCEP Reanalysis Model - Relative Humidity (Surface)

source: https://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.html

NCEP Reanalysis Model - Sea Level Pressure

source: https://www.esrl.noaa.gov/psd/data/gridded/data.ncep.reanalysis.html

Tropical Outgoing Longwave Radiation Anomalies (OLRA) During the Last 30 Days

source: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml

Time-Longitude Section of Anomalous OLR

source: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml

ESRL 30-Day Average OLR Anomaly

source: https://www.esrl.noaa.gov/psd/map/clim/olr.shtml

GHCN-M Global Monthly Temperature Anomaly

source: https://www.ncdc.noaa.gov/temp-and-precip/ghcn-gridded-products/

Current Total Precipitable Water and Winds

source: http://www.nrlmry.navy.mil/

GPM Three-Month-Mean Satellite-Derived Precipitation Anomalies

source: https://pmm.nasa.gov/data-access/downloads/gpm


IRI Multi-Model Probability Forecast for Temperature

source: http://iridl.ldeo.columbia.edu/maproom/Global/Forecasts/Temperature.html

IRI Multi-Model Probability Forecast for Precipitation

source: http://iridl.ldeo.columbia.edu/maproom/Global/Forecasts/Precipitation.html

CFSv2 Three-Month-Mean Spatial Anomalies (Outlook) - Surface Air Temperature

source: http://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml

CFSv2 Three-Month-Mean Spatial Anomalies (Outlook) - Precipitation

source: http://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml

NMME Three-Month-Mean Spatial Anomalies (Outlook) - Surface Air Temperature

source: http://www.cpc.ncep.noaa.gov/products/NMME/

NMME Three-Month-Mean Spatial Anomalies (Outlook) - Precipitation

source: http://www.cpc.ncep.noaa.gov/products/NMME/


Drought & Stream Flow

Hawaii Drought Area Percentage

source: http://www.ncdc.noaa.gov/sotc/drought/

USGS Monthly Streamflow for Hawaii

source: http://waterwatch.usgs.gov/?m=real&r=hi

Tropical Cyclones & Storms

Tropical Wind Anomalies During the Last 30 Days

source: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml

South Pacific Tropical Cyclone Tracks

source: http://weather.unisys.com/

NCEP Global Ocean Data Assimilation System (GODAS) - Tropical Cyclone Heat Potential

source: http://www.cpc.ncep.noaa.gov/products/GODAS/

West Pacific Tropical Cyclone Tracks

source: http://weather.unisys.com/

Global Tropical Hazards/Benefits Outlook

source: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ghazards/

East Pacific Tropical Cyclone Tracks

source: http://weather.unisys.com/

Sea-Surface Temperatures, Ocean Conditions, & Impacts


SST Anomaly Animations - Tropical Pacific

source: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml

SST Anomaly Animations - Equatorial Temperature Anomaly

source: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml

Subsurface SST Anomaly - Tropical Pacific

source: http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/enso.shtml

NCEP Global Ocean Data Assimilation System (GODAS) Animations - SST Anomaly

source: http://www.cpc.ncep.noaa.gov/products/GODAS/

TAO/TRITON SST and Winds - Past 21 Days

source: http://www.pmel.noaa.gov/tao/jsdisplay/

Coral Reef Watch Products - Bleaching Alert Areas

source: http://coralreefwatch.noaa.gov/satellite/baa.php

Coral Reef Watch Products - Coral Bleaching Hotspots

source: http://coralreefwatch.noaa.gov/satellite/hotspot.php

Coral Reef Watch Products - Degree Heating Weeks

source: http://coralreefwatch.noaa.gov/satellite/dhw.php

OceanWatch - Central Pacific: Aqua MODIS Ocean Color

source: http://oceanwatch.pifsc.noaa.gov

OceanWatch - Central Pacific: Aquarius Sea-Surface Salinity

source: http://oceanwatch.pifsc.noaa.gov

OceanWatch - Central Pacific: GOES-POES Sea-Surface Temperature

source: http://oceanwatch.pifsc.noaa.gov


CFSv2 Three-Month-Mean Spatial Anomalies (Outlook) - Sea-Surface Temperature

source: http://www.cpc.ncep.noaa.gov/products/CFSv2/CFSv2seasonal.shtml

NMME Three-Month-Mean Spatial Anomalies (Outlook) - Sea-Surface Temperature

source: http://www.cpc.ncep.noaa.gov/products/NMME/

Probability of Coral Bleaching Thermal Stress

source: http://coralreefwatch.noaa.gov/satellite/bleachingoutlook_cfs/outlook_cfs.php

Probablisitic Coral Bleaching Thermal Stress Warning

source: http://coralreefwatch.noaa.gov/satellite/bleachingoutlook_cfs/outlook_cfs.php

Sea-Level & Waves


OSTM/Jason-3 Satellite Sea Level Residuals - 10 Day Averages

source: http://sealevel.jpl.nasa.gov/science/elninopdo/latestdata/


Pacific Region Sea-Surface Heights

source: https://www7320.nrlssc.navy.mil/GLBhycom1-12/

WaveWatch III - Pacific Region Wave Height and Direction

source: http://polar.ncep.noaa.gov/waves/viewer.shtml?-multi_1-pacific-


ENSO & Other Climate Indices

Regional Partners

Pacific ENSO Applications Climate Center:
NOAA NWS Weather Forecast Office Honolulu :
NOAA NWS Weather Forecast Office Guam:
NOAA National Centers for Environmental Information:
NOAA NMFS Pacific Island Fisheries Science Center:
NOAA OceanWatch - Central Pacific:
NOAA Coral Reef Watch:
USGS Pacific Islands Water Science Center:
USGS Science Center - Pacific Coastal and Marine Science Center:
University of Hawaii - Joint Institute of Marine and Atmospheric Research:
University of Guam - Water and Environmental Research Institute:
University of Hawaii Sea Level Center:
University of Hawaii Asia-Pacific Data Research Center (APDRC)

Previous Climate Impacts and Outlook