Boise
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Boise Weather in May

With daytime temperatures of 22°C (72°F) and nighttime lows of 7°C (45°F), May in Boise brings high temperatures during the day. The excellent weather makes it an appealing time to visit.

Rainfall in Boise in May

Looking at the last 30 years, the data shows about 11 days with rain, averaging 33 mm (1.3 in) for the month. A fairly balanced picture this month, some wet days but nothing too extreme in terms of intensity.

Temperature in Boise in May

May is one of the better months to visit Boise. Expect 22°C (72°F) during the day and 7°C (45°F) at night. Overall, the month follows a fairly predictable daily temperature pattern. Nights fall to 7°C (45°F), which is cold enough to feel it indoors too. A good thick duvet makes all the difference for a comfortable night's sleep.

Sunshine in Boise in May

The days are predominantly sunny, with an estimated total of around 333 hours of sunshine. These sun-filled days are perfect for playing sports, visiting parks, or going for a bike ride.

If you're inclined towards comfortable temperatures and drier conditions, May is a good time to visit Boise.

Boise Temperature in May

Min Temperature
7°C (45°F)
Max Temperature
22°C (72°F)
Chance of Rain
35%
Precipitation
33 mm (1.3 in)
Rainy days
11 days
Humidity
48%
Sunshine
333 hours
Percentage Sunshine
74%

Boise Weather by Month

Pick a month to see the average temperature, rainfall and sunshine in Boise - and find the best time to visit.

Daily Historical Temperatures

50-year average (1976-2025)

Based on our historical records, temperatures in Boise typically rise from around 20°C (68°F) at the start of May to approximately 24°C (75°F) by the end. Nights are cool, with lows typically ranging from 6°C (43°F) to 11°C (52°F).

Average temperatures in May

Daily Historical Precipitation

50-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in May

Historical weather records for Boise in May

Browse day-by-day weather records for Boise spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.

Boise historical weather extremes in May

The extremes listed below come from historical weather data collected in Boise from 1976 through 2026.

  • Boise recorded its highest May temperature of 38°C (100°F) on May 31, 2025.
  • Nighttime temperatures dropped to -5°C (23°F) on May 2, 1988, marking the coldest May night on record.

Best Places in the United States of America in May

Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in May →

perfect weather
pleasant
tolerable
unpleasant
poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).

What to Wear in Boise in May

Pleasant temperatures in May mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Pack a light rain jacket or compact umbrella for occasional showers. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in Boise in May

We rated the following activities from 1 (least suitable) to 10 (best) to do.

  • Cycling
    10/10
  • Walking
    10/10
  • Barbeque
    9/10
  • Camping
    5/10
  • Outdoor sports
    10/10

Boise 3-Day Forecast

Popular in May

Where to go in May - average daytime high across popular destinations.

Bucket list

Need travel inspiration? Check out our bucket list articles and be inspired.