May weather forecastLewiston, ID
May
Weather in May
May experiences a considerable shift to welcomingly warm weather conditions in Lewiston. The rise in temperature does not bring excessive heat but rather the promise of a pleasant summer ahead. Longer daylight hours and a drop in humidity enhance the comfort level for residents. Although rainfall still remains a part of the weather pattern, the overall frequency noticeably decreases. The shift from spring to summer is visible through blossoming flora and the returned melody of chirping birds.Temperature
May's arrival coincides with a subtle temperature rise, moving from April's moderate 56.1°F (13.4°C) to a comfortable 65.1°F (18.4°C). In Lewiston, the May nights descend to a significantly cooler average of 42.6°F (5.9°C) compared to daytime highs.Humidity
The average relative humidity in May is 68%.Rainfall
In Lewiston, in May, it is raining for 13.6 days, with typically 1.42" (36mm) of accumulated precipitation. Throughout the year, there are 142.4 rainfall days, and 14.21" (361mm) of precipitation is accumulated.Snowfall
In Lewiston, snow does not fall in May through September.Daylight
In Lewiston, the average length of the day in May is 15h and 1min.On the first day of May, sunrise is at 5:32 am and sunset at 7:57 pm. On the last day of the month, sunrise is at 4:59 am and sunset at 8:32 pm PDT.
Sunshine
The average sunshine in May is 10.6h.UV index
In May, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 4 during May translates into the following directions:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Lewiston, ID
- Average high temperature in May: 65.1°F
The warmest month (with the highest average high temperature) is August (85.3°F).
The month with the lowest average high temperature is December (36.1°F).
- Average low temperature in May: 42.6°F
The month with the highest average low temperature is August (59.2°F).
The coldest month (with the lowest average low temperature) is December (24.4°F).
Average pressure in May
Lewiston, ID
- Average pressure in May: 29.95"Hg
The month with the highest atmospheric pressure is January (30.2"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in May
Lewiston, ID
- Average wind speed in May: 4.7mph
The windiest month (with the highest average wind speed) is April (5.7mph).
The calmest months (with the lowest average wind speed) are July, August and September (4.3mph).
Average humidity in May
Lewiston, ID
- Average humidity in May: 68%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is August (38%).
Average rainfall in May
Lewiston, ID
- Average rainfall in May: 1.42"
The wettest month (with the highest rainfall) is March (1.85").
The driest month (with the least rainfall) is August (0.31").
Average rainfall days in May
Lewiston, ID
- Average rainfall days in May: 13.6 days
The month with the highest number of rainy days is March (17.6 days).
The month with the least rainy days is August (5.2 days).
Average snowfall in May
Lewiston, ID
- Average snowfall in May: 0"
The month with the highest snowfall is February (3.27").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in May
Lewiston, ID
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is December (8.1 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Lewiston, ID
- Average daylight in May: 15h and 0min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in May: 10h and 36min
The month with the most sunshine is August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 5h and 6min).
Average sunshine days in May
Lewiston, ID
- Average sunshine days in May: 15.3 days
The month with the most sunshine days is July (24 days).
The months with the least sunshine days are February and March (10.8 days).
Average UV index in May
Lewiston, ID
- Average UV index in May: 4
The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in May
Lewiston, ID
- Average cloud cover in May: 30
The month with the most cloud cover is February (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in May
Lewiston, ID
- Average visibility in May: 6mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, February and December (5mi).
