Jacksonville woke up in a sweat Tuesday morning, with the KNIP observing station already reporting about 80°F before 6 a.m. and dewpoints hanging in the low 70s. The steamy start is not going anywhere fast. Expect a hot afternoon with highs near 95°F and heat-index readings climbing as high as 103°F by mid-afternoon. Scattered showers and thunderstorms are possible after about 1 p.m.; most should be brief, but a few stronger cells could kick out sudden downburst gusts strong enough to shove around patio furniture or small trees.
Afternoon Storms And Gusty Winds
Scattered storms are most likely from mid-afternoon into early evening, especially inland where the sea breeze meets the prevailing southerly flow. According to the National Weather Service Jacksonville, isolated strong storms could produce sudden downburst gusts up to 60 mph, and sustained south winds of 8–14 mph with higher gusts are possible. Even if a passing shower knocks temperatures down for a few minutes, the heat will stick around, with feels-like values in the low to mid 100s.
Marine And Beach Conditions
Offshore, seas will build toward 5–6 feet this afternoon, and a Small Craft Advisory is in effect from 2 p.m. Tuesday, July 21 to 5 a.m. Wednesday, July 22, so anglers and small-boat operators should avoid exposed waters. A moderate rip-current risk is expected along area beaches through Wednesday; swim only at lifeguarded beaches and steer clear of breaking waves. For background on the weeklong heat trend and storm chances, see our earlier coverage on steamy heat and pop-up storms.
Plan Ahead
Shift strenuous outdoor work to the morning hours, carry water, and take frequent shade breaks if you need to be outside this afternoon. Secure patio furniture and temporary structures before storms pop up, and move boats to protected moorings if possible. Keep a battery-powered radio or phone handy for sudden storm warnings, and put beach plans on hold if the surf looks rough.
Overnight And Wednesday
Overnight lows will hold near 78°F, with a lingering 20–30% chance of showers through early Wednesday morning. Wednesday should be drier overall, with highs near 96°F and heat-index values again reaching the low to mid 100s, although isolated afternoon storms return by late week. Keep an eye on local forecasts for updates as the Gulf system continues to influence humidity and storm chances.
