Sioux Falls, S.D. – Scorching summer heat is set to blanket Sioux Falls and much of South Dakota on Saturday, July 26th, pushing heat index values near 100°F and raising health concerns for residents and travelers. Outdoor plans will face the most intense heat this weekend, especially along I-29 and throughout the city.
According to the National Weather Service, Sioux Falls will climb to a high of 95°F on Saturday under mostly sunny skies. Heat index values in the 90s to low 100s will make outdoor activities potentially dangerous, especially for vulnerable groups. Authorities urge everyone to limit strenuous activities, hydrate frequently, and seek shade during peak afternoon hours. Emergency managers warn the hottest periods will likely be Sunday and Monday, and remind residents to check on elderly neighbors and pets.
A slight chance of thunderstorms returns Saturday night, continuing into Sunday night and Monday night. While severe weather risk remains low for now, lightning and sudden heavy rain could create travel hazards. The NWS highlights I-29 and local roads as possible trouble spots for quick downpours.
The hot and humid spell marks one of Sioux Falls’ most intense July weekends of 2025. Power companies recommend charging mobile devices and keeping air conditioners serviced, as elevated demand may cause brief outages. With repeated 90°F-plus highs, this pattern mirrors the mid-summer heatwaves of previous years.
What’s next?
Thunderstorm chances increase again Tuesday and Wednesday, with rain likely by midweek. Stay alert for updated advisories and avoid non-essential travel during storm periods.
Sioux Falls, SD Five-Day Weather Outlook (Starting Saturday, July 26th)
- Saturday: High 95°F, mostly sunny, humid. Slight storm chance overnight.
- Sunday: High 94°F, hot, slight chance of storms after dark.
- Monday: High 94°F, sunny, storm chances after 1 p.m., turning partly cloudy by night.
- Tuesday: High 85°F, scattered showers and storms, mainly before 1 p.m.; cooler by evening.
- Wednesday: High 77°F, 30% chance of showers; partly sunny.
- Thursday: High 76°F, mostly sunny, drier and cooler.
Warnings and advisories remain possible — check for updates throughout the week.
