San Antonio woke up cloudy, muggy and already in the low 80s on Friday, June 19, 2026, as the city heads into a Juneteenth combo of punishing heat and pop-up storms. A Heat Advisory runs from noon to 8:00 p.m. CDT, with heat index values expected to climb into the 108-112°F range while air temperatures top out near 93°F. Scattered showers and a chance of thunderstorms are likely in the early afternoon, and any stronger cells could bring brief heavy rain and gusty winds that may disrupt outdoor Juneteenth activities.
Afternoon Storm Risk
Shower and thunderstorm chances ramp up after 1:00 p.m., with stronger storms capable of producing quick downpours that could drop a quarter to a half inch of rain in spots. Lightning and sudden wind gusts will be the main hazards for people outdoors, and heavy rain may cut visibility and make roads slick. Keep a close eye on the sky this afternoon and be ready to move events indoors if thunderstorms start building nearby.
Heat Safety
According to the NWS Austin/San Antonio, the Heat Advisory is in effect from noon to 8:00 p.m. CDT and calls for "heat index values of 108 to 112" across much of the area. If you do not have reliable air conditioning, the City of San Antonio maintains a list of cooling centers and heat-relief resources to help residents find a safe place to cool down. Drink plenty of water, skip or scale back strenuous activity during the advisory hours, and never leave people or pets in a closed vehicle.
Weekend Outlook
Pop-up showers remain possible Saturday afternoon with a high near 91°F, then a drier, warmer pattern builds Sunday into next week with highs climbing into the mid-90s. Sunday will be breezier, with south winds around 10 to 15 mph and gusts as high as 25 mph, so expect dusty conditions in some spots. Forecasters say the subtropical ridge will strengthen by Monday, raising heat concerns again across the I-35 corridor.
Plan Ahead For Events
If you are attending or organizing Juneteenth gatherings, prioritize shade, steady hydration and a plan to get people under solid shelter quickly if storms fire up this afternoon. Check with event organizers for any schedule tweaks, move strenuous activities to early morning when you can, and follow later updates from local officials and forecasters before heading out.
