Located in the heart of the Boise Valley and at an elevation of 2,440-2,470 feet, Nampa enjoys a mild climate year round. Its high desert location is bordered to the north by the Front Range of the Rocky Mountains and to the south by the Owyhee Mountains. On average, there are 210 sunny days per year in Nampa, ID.
Climate
Nampa, ID
Annual Rainfall (inches)
11.6
Max. Rainfall within 24 hours (inches)
1-2
Annual Snowfall (inches)
19.1
Max. Snowfall within 24 hours (inches)
3-4
Precipitation Days
86
Number of days of elevated smog conditions
Low
Number of days of poor visibility and low ceiling
January is month with lowest average visibility at 6.1 miles. July visibility averages 10 miles.
Prevailing winds direction
27% from SE, 22% from the NW, & 10% from W
Mean wind speed by month
January 7mph, April 9mph, July 8mph, October 7mph
Peak gust speed by month and year
Highest average wind speed of 9mph occurs around March 25, where average daily max is 17mph. Over course of year, wind speeds vary from 0-17mph, rarely exceeding 24mph
Sunny Days
210
Avg. July High
91
Avg. Jan Low
21.1
Humidity Factors By Month
Low Humidity. Highest levels in winter. January - 67%, April 30%, July 17%, October 30%
UV Index
4
Elevation ft.
2440-2470
Natural Disaster
Frequency
Severity/Rating
Floods
Rare
Tornadoes
No historical tornado events
Tornado Index Boise City/Nampa 12.94 US 136.45
Hail Storms
Rare
Hurricanes
Rare
Other Major Storms
In past 60 years - Rare thunderstorms with wind and hail Wildfire, in region
Earthquakes
Rare
No historical earthquakes above 3.5 magnitude or above