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 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's arrival coincides with a subtle temperature rise, moving from April's moderately hot 74.8°F (23.8°C) to a still warm 82.8°F (28.2°C). Nighttime temperatures exhibit a substantial dip from daytime highs during May, averaging at a mild 57°F (13.9°C).Heat index
Throughout May, the heat index is appraised at 82.4°F (28°C). Prolonged exposure combined with continuous activity could lead to exhaustion, and possibly heat cramps.Be advised, the heat index considers values for conditions in shade and with a light breeze. When exposed to the direct sun, the heat index may augment by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', melds the effects of warmth and moisture to generate a feeling of heat. Elements of metabolic variation, physical activity, and clothing contribute to the effect of temperature on an individual. With the sun shining directly, it's crucial to understand that it can increase the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. Young ones are generally more prone to risk than adults due to their reduced ability to sweat. Their large skin surface area relative to their diminutive bodies and elevated heat production from their activities further enhance this risk.
Humidity
In Riverdale, the average relative humidity in May is 43%.Rainfall
In Riverdale, in May, it is raining for 4 days, with typically 0.51" (13mm) of accumulated precipitation. In Riverdale, during the entire year, the rain falls for 58.2 days and collects up to 9.29" (236mm) of precipitation.Daylight
The average length of the day in May is 14h and 7min.On the first day of May, sunrise is at 6:05 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 5:42 am and sunset at 8:11 pm PDT.
Sunshine
In Riverdale, the average sunshine in May is 11.6h.UV index
In Riverdale, the average daily maximum UV index in May is 6. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for the average person.Note: The maximum daily UV index, 6 in May, converts into the following recommendations:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. The Sun emits the most powerful UV radiation between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How hot is it in May?
What is the average humidity in May?
How many days does it rain in May in Riverdale?
What is the average length of the day in May in Riverdale?
What time are sunrise and sunset in May?
How many hours of sunshine does Riverdale have in May?
How high is the UV index in May?
Average temperature in May
Riverdale, CA
- Average high temperature in May: 82.8°F
The warmest month (with the highest average high temperature) is July (102.2°F).
The month with the lowest average high temperature is December (57.2°F).
- Average low temperature in May: 57°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is December (43°F).
Average pressure in May
Riverdale, CA
- Average pressure in May: 29.94"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in May
Riverdale, CA
- Average wind speed in May: 6.6mph
The windiest month (with the highest average wind speed) is June (7.1mph).
The calmest months (with the lowest average wind speed) are January and November (4.8mph).
Average humidity in May
Riverdale, CA
- Average humidity in May: 43%
The months with the highest relative humidity are January and December (66%).
The month with the lowest relative humidity is July (30%).
Average rainfall in May
Riverdale, CA
- Average rainfall in May: 0.51"
The wettest months (with the highest rainfall) are January, February and March (1.54").
The driest month (with the least rainfall) is August (0.08").
Average rainfall days in May
Riverdale, CA
- Average rainfall days in May: 4 days
The month with the highest number of rainy days is March (9.6 days).
The month with the least rainy days is August (0.8 days).
Average daylight in May /
Average sunshine in May
Riverdale, CA
- Average daylight in May: 14h and 1min
The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in May: 11h and 4min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 24min).
Average sunshine days in May
Riverdale, CA
- Average sunshine days in May: 26.4 days
The month with the most sunshine days is August (29.3 days).
The month with the least sunshine days is February (19.4 days).
Average UV index in May
Riverdale, CA
- Average UV index in May: 6
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are January, November and December (UV index 3).
Average cloud cover in May
Riverdale, CA
- Average cloud cover in May: 15
The months with the most cloud cover are March and December (Cloud cover 28).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in May
Riverdale, CA
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Riverdale, California, USA
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