Idaho local data guide

Average Temperatures for Boise, Idaho in Late July

In late July, Boise experiences some of its warmest weather of the year, characterized by a dry, semi-arid climate. According to 1991–2020 climatological normals, typical daily highs reach approximately 93°F, while average daily lows hover around 62°F.

Updated with grounded research as of 2026-09-16.

The short answer

Late July is historically the hottest part of the summer in Boise, Idaho. Based on the 1991–2020 climate normals, residents and prospective movers can expect daily high temperatures to average 93°F, with cooler overnight lows averaging 62°F. This period is typically dry, reflecting the region's semi-arid high desert environment.

Key facts

Average Daily High (July)
93°F
Average Daily Low (July)
62°F
Average Monthly Temperature (July)
77.1°F

Understanding Boise's Summer Climate

Boise sits in a high desert basin, which significantly influences its summer weather patterns. While daytime temperatures are consistently warm to hot in late July, the lack of humidity means that heat is generally perceived differently than in more tropical climates. The significant 'diurnal temperature variation'—the difference between the daily high and low—is a hallmark of this region, allowing for relatively cool and comfortable evenings even after very hot afternoons.

Planning for Local Housing and Lifestyle

When planning a move to or within Boise, it is helpful to consider how these temperatures impact home utility and energy needs. Homes in the area are typically equipped with central air conditioning to manage the July heat. Prospective homeowners often prioritize properties with adequate cooling infrastructure, energy-efficient windows, or strategic landscaping that provides shade during the peak afternoon sun.

Important Considerations for Residents

While averages provide a baseline, they do not capture the variability of weather year-to-year. Boise can experience 'heat waves' where temperatures stay well above the 93°F average for several days. Conversely, mountain breezes and the surrounding topography can create localized variations in temperature across the Treasure Valley. Residents are encouraged to monitor seasonal forecasts when planning outdoor activities or construction projects during late summer.

Common questions

Is late July the hottest time of year in Boise?

Yes, late July is historically the hottest period of the year for Boise, Idaho, coinciding with the peak of the summer season before temperatures begin a gradual decline in late August.

Does Boise experience high humidity during July?

No, Boise has a semi-arid climate, meaning humidity levels are generally low throughout the summer. This dry heat can make high temperatures feel more manageable than they would in humid regions.

Related Idaho questions

  • What is the average annual precipitation in Boise?
  • What are the typical seasonal temperature ranges in Boise?

Sources and verification