textproduct: Key West

KEY MESSAGES

-Rain chances near nil expected through Saturday night. -Coldest air of the season this weekend due to radiational cooling effects! Morning temperatures in the lower to mid 50s across the Upper and Lower Keys where wind went calm and lower 60s for the Middle Keys.

-A slow moderating trend is expected to begin today at least in relation to daytime highs with temperatures rebounding to near 70 degrees and lower 70s for Saturday.

DISCUSSION

Issued at 954 AM EST Fri Jan 2 2026 The first Friday of the year opened with a nearly clear sky across the Florida Keys. The arctic air mass that surged south into the eastern US is still in place, and colder than normal temperatures will persist for at least another 24 hours. Across the Keys, temperatures were able to drop into the lower 50s. The low temperature measured at the KKEY office was 52 F this morning. Breezes along the reef are light to gentle with the strongest winds off the Upper Keys. No immediate changes are expected based on the morning 12Z sounding either. Multiple subsidence inversions will keep skies clear of cloud cover, and the lack of strong cold air advection based on weak low level winds means decks of stratus clouds will struggle to form. Sampled precipitable water was also close to the tenth percentile for the day. Considering the lower temperatures, weak breezes, and lack of meteorological objects on the KBYX radar, we are expecting a very uneventful day for weather across the Keys.

Upstream, a couple of features highlight how the pattern will begin to change. Low pressure systems developing over the southeastern States will help push a high pressure system over the Gulf into the Atlantic. Until then, the high will remain near the Keys. Winds tonight are forecast to be light and variable, meaning the larger islands will be able to radiate into the 50s. Some islands may get into the lower 50s, so make sure to have additional layers on hand!

AVIATION

(12Z TAFS) Issued at 954 AM EST Fri Jan 2 2026 VFR conditions will prevail at both EYW and MTH. Breezes will remain light and variable throughout the TAF period.

FORECAST

High pressure over the central Gulf will continue to slowly move overhead by this afternoon. This will lead to light to gentle north to northeast breezes becoming light and variable. The high will remain overhead into the weekend maintaining the light and variable breezes through at least Saturday evening. While daytime highs are expected to continue rebounding through the weekend, the same cannot be said for overnight. Due to the light and variable flow, there is a high likelihood for temperatures to be able to radiate each night. Therefore, temperatures may still be able to fall into the lower to mid 50s for some of the larger islands of the Keys, including the normally cooler spots. There is an outside chance, one or two locations may be able to cool down to near 50 degrees, especially if the wind goes completely calm for a few to several hours. Also, the dew points won't start to increase until the second half of the weekend. Temperatures rise back to near normal during the second half of the weekend into early next week. Normal is highs in the mid 70s and overnight lows in the lower to mid 60s. Dry air will remain entrenched across the Keys through the period leading to nil rain chances through Saturday.

Confidence continues to grow for a subtle front to press through the Keys sometime late Sunday/Sunday evening which is a slow down from previous forecasts. Numerical guidance remains the same though in terms of this front. The front will mostly result in a wind shift rather than a dip in dew points. In addition, moisture will try and pool ahead of the front. Therefore, slight chance of showers (10%) return to the forecast for Sunday. Rain chances have been removed from Saturday night due to the slower moving nature of the front.

High pressure will dominate the eastern United States behind the front as it moves out into the Atlantic by mid to late week. This will result in a northeast to east flow through the extended. Dry air will remain across the Keys behind the front leading to nil rain chances.

If you are wondering when things might start to really warm up, a sneak peak at the end to the first full week of 2026 shows hints of upper level ridging building across much of Florida. This would result in temperatures rising to above normal for approximately Thursday through the following weekend. Early signs show temperatures approaching the upper 70s to potentially 80 degrees and rising humidity. Stay tuned!

MARINE

Issued at 430 AM EST Fri Jan 2 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, high pressure over the central Gulf will maintain light to gentle north to northeast breezes this morning. As the high moves overhead this afternoon, breezes will become light and variable. A weak front is expected to pass through the Key late Sunday/Sunday evening with a return of northerly breezes. In the wake of the front, high pressure will slide across the eastern United States. This will maintain northeast breezes initially before becoming mainly easterly as the high moves out into the Atlantic.

CLIMATE

On this day in 1898, the daily record low temperature of 47F was recorded at Key West. Temperature records for Key West date back to 1872.

PRELIMINARY POINT TEMPS/POPS

Key West 70 62 73 67 / 0 0 0 10 Marathon 69 61 72 64 / 0 0 0 10

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...None.