Great Falls in May

7.3out of 10

Possible, with caveats

Mild: highs around 20°C. Frequent rain: about 11 rainy days.

20°CAvg high
6°CAvg low
11Rainy days (61 mm)
14:54 hDaylight
05:54Sunrise · 20:49 Sunset

Why this score

  • Mild: highs around 20°C
  • Frequent rain: about 11 rainy days

What to wear and pack

  • Layers you can add or remove
  • Rain jacket or compact umbrella

How reliable is the forecast?

Rain in May varies a lot between years (±3.1 rainy days), so check the forecast closer to your trip. Averages cover 30 years (1991–2020). Individual days can differ a lot.

Year at a glance

1° -7° J 3° -7° F 9° -3° M 14° 2° A 20° 6° M 24° 10° J 30° 14° J 30° 13° A 23° 9° S 15° 3° O 7° -2° N 1° -6° D Rainy days

Weather by month

MonthAvg highAvg lowRainfall Rainy daysHumiditySunshine Score
January 1°C-7°C20 mm 6– – 4.4
February 3°C-7°C19 mm 6– – 4.8
March 9°C-3°C26 mm 7– – 5.7
April 14°C2°C52 mm 9– – 6.5
May 20°C6°C61 mm 11– – 7.3
June 24°C10°C73 mm 10– – 7.7
July 30°C14°C24 mm 5– – 8.1
August 30°C13°C28 mm 5– – 8.3
September 23°C9°C36 mm 6– – 8.3
October 15°C3°C34 mm 6– – 7.1
November 7°C-2°C23 mm 6– – 5.6
December 1°C-6°C21 mm 6– – 4.5

Frequently asked questions

How hot is Great Falls in May?

Daytime highs average 20°C and nights about 6°C.

When is the best time to visit Great Falls?

The best months are August, September, July.