Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
May introduces a minor temperature shift, with average high-temperatures adjusting from April's pleasant 68°F (20°C) to a moderately hot 74.1°F (23.4°C). During May, Saint Helena notes a substantial drop from the daytime peak to an average minimum temperature of 46.9°F (8.3°C).Humidity
In Saint Helena, the average relative humidity in May is 64%.Rainfall
In Saint Helena, in May, it is raining for 5.7 days, with typically 0.87" (22mm) of accumulated precipitation. Throughout the year, there are 76.2 rainfall days, and 16.93" (430mm) of precipitation is accumulated.Snowfall
January, February, April through December are months without snowfall.Daylight
In May, the average length of the day is 14h and 17min.On the first day of the month, sunrise is at 6:11 am and sunset at 8:02 pm. On the last day of May, sunrise is at 5:47 am and sunset at 8:27 pm PDT.
Sunshine
In Saint Helena, the average sunshine in May is 10.2h.UV index
In Saint Helena, California, the average daily maximum UV index in May is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for the average person.Note: The daily high UV index of 5 during May translates into the following recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average May temperature?
What is the average humidity in May?
How many days does it rain in May?
When it does not snow?
What is the average length of the day in May in Saint Helena?
When is the sunrise / sunset in May?
How long on average sun shines in May?
What is the UV index reading in May?
Average temperature in May
Saint Helena, CA
- Average high temperature in May: 74.1°F
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is December (54.5°F).
- Average low temperature in May: 46.9°F
The month with the highest average low temperature is September (54.3°F).
The coldest month (with the lowest average low temperature) is December (39.6°F).
Average pressure in May
Saint Helena, CA
- Average pressure in May: 29.97"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).
Average wind speed in May
Saint Helena, CA
- Average wind speed in May: 5.8mph
The windiest month (with the highest average wind speed) is May (5.8mph).
The calmest month (with the lowest average wind speed) is November (4.3mph).
Average humidity in May
Saint Helena, CA
- Average humidity in May: 64%
The month with the highest relative humidity is March (76%).
The month with the lowest relative humidity is September (53%).
Average rainfall in May
Saint Helena, CA
- Average rainfall in May: 0.87"
The wettest month (with the highest rainfall) is February (3.7").
The driest month (with the least rainfall) is July (0").
Average rainfall days in May
Saint Helena, CA
- Average rainfall days in May: 5.7 days
The month with the highest number of rainy days is March (13.5 days).
The month with the least rainy days is August (0.3 days).
Average snowfall in May
Saint Helena, CA
- Average snowfall in May: 0"
The month with the highest snowfall is March (0.04").
The months with the least snowfall are January, February, April, May, June, July, August, September, October, November and December (0").
Average snowfall days in May
Saint Helena, CA
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is March (0.2 days).
The months with the least snowfall days are January, February, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in May /
Average sunshine in May
Saint Helena, CA
- Average daylight in May: 14h and 2min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in May: 10h and 1min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in May
Saint Helena, CA
- Average sunshine days in May: 24.2 days
The month with the most sunshine days is July (30 days).
The month with the least sunshine days is March (15.9 days).
Average UV index in May
Saint Helena, CA
- Average UV index in May: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in May
Saint Helena, CA
- Average cloud cover in May: 29
The month with the most cloud cover is March (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in May
Saint Helena, CA
- Average visibility in May: 6mi
The months with the highest visibility are February, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January and March (5mi).
Saint Helena, California, USA
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