Climate Summary
The Dog Days of Summer this year officially run from July 3 through August 11, 2025. They are named as such as this 40-day period coincides with the sunrise rising of Sirius, the Dog Star. They line up course, with the sweltering days of summer, and this year has been especially oppressive. July average temperatures ran 2-4°F above normal, with overnight lows running 4-6°F above average for most counties. Humidity levels have been at record levels. For instance, from June 1 – July 31, Dayton International Airport recorded a dewpoint temperature at or above 65°F 66% of the time (957 hours) and 35% of the time (509 hours) with a dewpoint temperature at or above 70°F. Both of these observations are records for this location over the last 76 years (1950-2025).
Precipitation over the last 30 days has been highly variable (Figure 1). Most locations have picked up 3-6 inches of rain with locally heavier totals in portions of north central, southwest, and southeast Ohio. While no significant drought concerns exist, pockets of dryness are evident across parts of Van Wert, Paulding, Henry, Wood, Putnam, Hancock, and Ashtabula Counties. For the latest up-to-date conditions, seasonal outlooks, and monthly climate summaries, please visit the State Climate Office of Ohio.
Figure 1: Total precipitation over the last 30 days ending August 3, 2025. Figure courtesy of the Iowa Environmental Mesonet.
Weather Forecast
This past weekend brought absolutely delightful weather to the Buckeye State. Low humidity and overnight lows in the upper 40s to mid 50s was a welcome break from the heat and humidity this summer. High pressure has now shifted east, and while the flow has been out of Canada the last few days (thus the hazy skies from wildfires), a southerly wind is taking over. This will lead to warming temperatures this week with highs mainly in the 80s and lows in the 60s. We could push 90°F for a few locations over the weekend. Despite the return flow, precipitation is expected to be relatively light (Figure 2). A few isolated showers and storms are possible through Thursday, mainly across southern Ohio. Additional isolated storms are possible over the weekend. Overall, the National Weather Service is currently forecasting up to 0.25 inch for northern and eastern counties, and 0.1-0.5 inch for southwest Ohio. As is the case in summer, locally heavier totals are possible where thunderstorms occur.
Figure 2: Total precipitation forecast for the period 8pm August 4 – 8pm August 11. Figure courtesy of the National Weather Service-Wilmington, Ohio.
The 8-14 day outlook from the Climate Prediction Center for the period of July 29 – August 4 and the 16-Day Rainfall Outlook from NOAA/NWS/Ohio River Forecast Center show increased probability of above normal temperatures and precipitation are favored (Figure 3). Climatological normals for this period include a high-temperature range of 81-85°F, a low-temperature range of 61-65°F, and weekly total precipitation of 0.70 - 0.90 inches.
Figure 3) Climate Prediction Center 8-14 Day Outlook valid for August 11 – 17, 2025, for left) temperatures and right) precipitation. Colors represent the probability of below, normal, or above normal conditions.