BILLINGS — A stretch of very hot days is set to settle over south-central and southeast Montana, with temperatures climbing into the upper 90s and lower 100s beginning Friday and continuing well into next week. The prolonged heat, warm overnight lows, increasing fire danger, and periodic thunderstorm chances will be the main weather concerns through the end of July.
FRIDAY
Hotter and drier conditions arrive as a strengthening ridge of high pressure builds over the region. High temperatures will reach the upper 90s to lower 100s across much of the area, marking the beginning of an extended heat wave. Relative humidity will drop into the teens while breezy west winds develop, increasing fire weather concerns as fuels continue to dry. Overnight temperatures will remain unusually warm, limiting nighttime relief from the heat.
SATURDAY
Saturday looks to be one of the hottest and most concerning days of the period. Afternoon temperatures are expected to reach 100 to 105 degrees in many locations, with Billings potentially topping 100 degrees for the first time ever on July 25. Scattered high-based thunderstorms are expected to develop during the afternoon and evening. While rainfall will be spotty, storms may produce frequent lightning and strong, erratic wind gusts. The combination of extreme heat, low humidity, lightning, and gusty outflow winds has prompted a Fire Weather Watch for much of the area.
SUNDAY
Hot and generally dry weather continues with highs remaining near or above 100 degrees in many locations. Thunderstorm chances decrease somewhat compared to Saturday, though an isolated storm remains possible. A weak backdoor front may bring a shift to northerly winds, especially across eastern zones, where breezy conditions could briefly develop. Elevated fire concerns will continue due to the combination of heat and dry conditions.
MONDAY
The upper-level ridge remains firmly in control, keeping temperatures well above normal. Highs from the mid-90s to lower 100s are expected area-wide. A slight chance of afternoon and evening thunderstorms develops, mainly over higher terrain before drifting into surrounding areas. Any storms that form will be capable of producing gusty winds and lightning despite limited rainfall.
TUESDAY
Little change is expected as the persistent ridge continues. Temperatures remain dangerously hot, and warm nighttime lows will continue to increase the risk of heat-related illness for those without adequate cooling. Isolated afternoon and evening thunderstorms remain possible, with lightning and gusty winds posing concerns for new fire starts.
WEDNESDAY
Above-normal temperatures continue with highs in the 95 to 105 degree range. Moisture levels remain slightly above seasonal averages, allowing for a low chance of afternoon thunderstorms. While storms may produce some rainfall, they will also be capable of generating erratic wind gusts and lightning, maintaining elevated fire weather concerns.
THURSDAY
The pattern shows little sign of changing as the strong ridge remains anchored over the Intermountain West. Hot temperatures persist across the region with only isolated thunderstorm chances during the afternoon and evening. Forecast guidance suggests any meaningful break from the heat will likely hold off until sometime in August.
Stay safe if spending time outdoors over the next week. Limit strenuous activity during the hottest part of the day, stay hydrated, check on vulnerable individuals, and remain alert for rapidly changing fire and thunderstorm conditions.
