Glenn James
Hawaii Weather Today
Founder and maintainer for 30 years


The latest update to this website was 418am Sunday HST


Here are the latest 24-hour precipitation totals (inches) for each of the islands Sunday morning:

0.15  Moloaa Dairy, Kauai
0.08  Punaluu Stream, Oahu
0.01  Keopukaloa, Molokai
0.00  Lanai
0.06  West Wailuaiki, Maui
0.27  Honolii Stream, Big Island


The following numbers represent the strongest wind gusts (mph) Sunday morning:

20  Port Allen, Kauai – ESE
23  Oahu Forest NWR, Oahu – ESE
23  Makapulapai, Molokai – E
24  Lanai 1,  Lanai – NE
20  Mamane Pl, Maui – W
16  Kealakomo, Big Island – NE


Hawaii’s Mountains – Here’s a link to the live webcam on the summit of our tallest mountain Mauna Kea (~13,800 feet high) on the Big Island of Hawaii. Here’s the webcam for the (~10,023 feet high) Haleakala Crater on Maui. These webcams are available during the daylight hours here in the islands, and at night whenever there’s a big moon shining down. Also, at night you will be able to see the stars, and the sunrise and sunset too…depending upon weather conditions.

https://weather.gc.ca/data/satellite/goes_gwdisk11_1070_100.jpg

Big Blue…click twice for largest version

 

https://cdn.star.nesdis.noaa.gov/GOES18/ABI/SECTOR/hi/GEOCOLOR/20261090500-20261091250-GOES18-ABI-HI-GEOCOLOR-600x600.gif

 High level clouds moving over the state…from the west

 

https://radar.weather.gov/ridge/standard/HAWAII_loop.gif

https://radar.weather.gov/ridge/standard/PHKI_loop.gif

https://radar.weather.gov/ridge/standard/PHKM_loop.gif

Showers locally 

 

https://www.weather.gov/wwamap/png/hfo.png

Please open this link to see details on the current Watches, Warnings and Advisories noted above




~~~ Hawaii Weather Narrative ~~~

 

Glenn’s Sunday comments:  I’m here in Corte Madera, Marin County, California with my friends Bob and Linda, continuing on in my working vacation.

 

>>> Highest Temperature Saturday, April 18, 2026 – 97 degrees near Horrel Hill, SC
>>> Lowest Temperature Sunday, April 19, 2026 –  5 degrees at Peter Sinks, Utah

 

Interesting weather Web Blog: Mauka Showers…Mother Nature Reminds Us that April is Still in the Wet Season

 

Hawaii’s Broad Brush Weather Overview…as of Sunday morning: An upper-level trough will bring increased high clouds and renewed chances for isolated heavy showers and thunderstorms this afternoon and Monday. Light winds favor chances for mainly afternoon showers Tuesday and Wednesday, followed by rebuilding trade winds Thursday and Friday.

Weather Details for the Hawaiian Islands…as of Sunday morning: Today and tomorrow, trades will weaken further and will shift out of the east-southeast across the western half of the island chain, while another upper-level trough brings instability, mainly tonight into Monday morning. For now, it appears that the deepest moisture and greatest chances for widespread rainfall will remain along the surface trough northwest of Kauai, but isolated heavy showers or a thunderstorm remain possible around Kauai.

Elsewhere, expect afternoon interior showers and possibly a thunderstorm on Big Island, and another item to monitor will be a chance for localized anchored heavy showers along the Koolau Mountains of Oahu tonight. Even though moisture does not appear to be significant on Oahu, the expected veering flow with height has a tendency to produce heavy rain events on the Koolau. Chances for heavy rainfall look to diminish Tuesday and Wednesday.

The upper level trough should move off to the east late Monday, allowing a weak ridge aloft to settle over the state. The GFS and ECMWF models are hinting that the surface trough, that had been lingering northwest of Kauai will be pushed over the western end of the island chain. This would favor light and variable winds over most areas with higher rainfall chances over island interiors during the late morning and afternoon hours. Trade winds are expected to rebuild Thursday and Friday.


Here’s a near real-time Wind Profile of the Pacific Ocean – along with a Closer View of the islands / Here’s the latest Weather Map / Looping Surface Precipitation…through the next 8-days

 

Marine Environmental Conditions…as of Sunday: A high pressure system far north of the state will slowly drift eastward this weekend. Easterly trade winds diminish tonight, as a trough to the northwest of the islands develops into a weak low pressure system. The resulting weakness in the ridge causes winds to veer southeasterly and diminish over the western Hawaii islands into early in the new week.

By Thursday the high pressure ridge builds back in north of the state, with fresh easterly trade winds returning to the region lasting through next weekend. A small pulse of medium period swell energy from the northwest should produce a slight bump in north facing surf heights. Another small, medium period northwest swell will move into the region by Monday night and continue through Wednesday. A moderate, medium period northeast swell arrives Tuesday and peaks on Wednesday, bringing moderate surf to north-facing shores, before slowly declining through the end of the week.

A series of overlapping small south swells will move into the region this week, keeping surf heights on the small side.

Surf heights along east facing shores also remain small due to weaker trade winds, until the arrival of the small, medium period northeast swell building into the Hawaii area Tuesday through Thursday.

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Wailea beach path, Wailea Elua, Ulua Beach


World-wide Tropical Cyclone Activity


>>> Here’s a link to the latest Pacific Disaster Center’s Weather Wall


>>> Atlantic Ocean: There are no active tropical cyclones

>>> Caribbean Sea: There are no active tropical cyclones

>>> Gulf of Mexico: There are no active tropical cyclones

Here’s the link to the National Hurricane Center (NHC)

 

>>> Eastern Pacific: There are no active tropical cyclones

Here’s the link to the National Hurricane Center (NHC)

>>> Central Pacific: There are no active tropical cyclones

Here’s the link to the Central Pacific Hurricane Center (CPHC)

 

>>> Northwest Pacific Ocean:

Tropical Cyclone 04W (Sinlaku)…is located approximately 247 NM north of Minami Tori Shima

https://www.metoc.navy.mil/jtwc/products/04W_191200sair.jpg

 

>>> Southwest Pacific Ocean: There are no active tropical cyclones

>>> North and South Indian Oceans / Arabian Sea: There are no active tropical cyclones



Interesting: When Does the Body Clock Begin to Synchronize with Local Time?

Daily rhythms cross placenta from mother to the baby before the fetus can sense light.

Humans and most other organisms have internal biological clocks that track the daily cycle of sunrise and sunset. These clocks help time our sleep, metabolism and other essential body functions over the course of a day, creating daily patterns called circadian rhythms. Research shows that when these rhythms are disrupted — by jet lag, lack of sleep or irregular work schedules — people can suffer long-term negative health effects.

Scientists who study daily rhythms have long wondered about when the mammalian circadian clock starts ticking and synchronizes to local time. In a new study published in the Journal of Biological Rhythms, researchers at Washington University in St. Louis reported that a mother helps to set the biological clock for her babies while they are still in the womb.

“We know that disrupting circadian rhythms during pregnancy can affect how sleep and daily rhythms develop in infants, and these early disruptions are linked to a higher risk of mood disorders such as anxiety and depression later in life,” said Nikhil Lokesh, study author and a research scientist in biology in WashU Arts & Sciences. “Understanding when the fetal clock begins to function helps us identify sensitive developmental windows when circadian disruption may have lasting effects and how those effects might be prevented or corrected.”

Read More: Washington University in St. Louis