May weather forecast and climate
Riverdale, CA

Weather in May

May, the last month of the spring, in Riverdale, is another warm month, with average temperature ranging between min 57°F (13.9°C) and max 82.8°F (28.2°C).

Temperature

In May, the average high-temperature slightly increases, from a moderately hot 74.8°F (23.8°C) in April, to a still warm 82.8°F (28.2°C). The average low-temperature, in Riverdale, is 57°F (13.9°C).

Heat index

The average heat index is appraised at 82.6°F (28.1°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'felt air temperature', 'real feel', or 'feels like', is calculated by taking the relative humidity value for a specific location and factoring it into the air temperature reading. This effect is individual, with diverse people perceiving weather differently for numerous reasons (differences in body mass, height, and shape, metabolic differences, clothing), and activity. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

In May, the average relative humidity is 43%.

Rainfall

In Riverdale, California, during 4 rainfall days, 0.51" (13mm) of precipitation is typically accumulated. Throughout the year, there are 58.2 rainfall days, and 9.29" (236mm) of precipitation is accumulated.

Daylight

The average length of the day in Riverdale, California, is 14.1h.

Sunshine

In May, the average sunshine in Riverdale is 11.6h.

UV index

The average daily maximum UV index in Riverdale is 6. A UV Index reading of 6 to 7 represents a high health risk from the exposure to the Sun's UV radiation for the ordinary person.
Note: The daily maximum UV index of 6 interpret into the following advice:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the temperature in May in Riverdale?

In May, in Riverdale, California, the average high-temperature is 82.8°F (28.2°C), and the average low-temperature is 57°F (13.9°C). The average heat index (a.k.a. 'feels like', 'real feel'), that takes the relative humidity and factores it into the air temperature reading, in May is evaluated at 82.6°F (28.1°C).

What is the average humidity in May in Riverdale?

In May, the average relative humidity in Riverdale, California, is 43%.

How many days does it rain in May in Riverdale?

In Riverdale, during May, the rain falls for 4 days and regularly aggregates up to 0.51" (13mm) of precipitation.

How many hours of daylight does Riverdale have in May?

The average length of the day in May in Riverdale is 14.1h.

How long on average sun shines in May in Riverdale?

In Riverdale, California, the average sunshine in May is 11.6h.

What is the UV index reading in May in Riverdale?

In Riverdale, the average daily maximum UV index in May is 6. A UV Index value of 6 to 7 symbolizes a high health risk from the exposure to the Sun's UV rays.

Average temperature in May
Riverdale, CA

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).

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Average pressure in May
Riverdale, CA

Average pressure in May - Riverdale, CA
  • Average pressure in May: 29.94"

The month with the highest atmospheric pressure is January (30.14").
The month with the lowest atmospheric pressure is June (29.89").

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Average wind speed in May
Riverdale, CA

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).

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Average humidity in May
Riverdale, CA

Average humidity in May - Riverdale, CA
  • Average humidity in May: 43%

Months with the highest relative humidity are January and December (66%).
The month with the lowest relative humidity is July (30%).

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Average rainfall in May
Riverdale, CA

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").

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Average rainfall days in May
Riverdale, CA

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).

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Average daylight in May /
Average sunshine in May
Riverdale, CA

Average daylight in May / Average sunshine in May - Riverdale, CA
  • Average daylight in May: 14.1h

The month with the longest days is June (Average daylight: 14.6h).
The month with the shortest days is December (Average daylight: 9.7h).

  • Average sunshine in May: 11.6h

Months with the most sunshine are June and July (Average sunshine: 12.1h).
The month with the least sunshine is December (Average sunshine: 6.4h).

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Average sunshine days in May
Riverdale, CA

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).

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Average UV index in May
Riverdale, CA

Average UV index in May - Riverdale, CA
  • Average UV index in May: 6

Months with the highest UV index are June, July and August (UV index 7).
Months with the lowest UV index are January, November and December (UV index 3).

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Average cloud cover in May
Riverdale, CA

Average cloud cover in May - Riverdale, CA
  • Average cloud cover in May: 15

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).

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Average visibility in May
Riverdale, CA

Average visibility in May - Riverdale, CA
  • Average visibility in May: 6mi

Months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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