May weather forecast
Lewiston, CA

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Weather in May

May, the last month of the spring in Lewiston, is an enjoyable month, with an average temperature varying between 39.9°F (4.4°C) and 64.9°F (18.3°C).

Temperature

A subtle rise in the average high-temperature is observed during May, adjusting from a moderate 56.3°F (13.5°C) in April to a comfortable 64.9°F (18.3°C). Lewiston sees a consistent average low-temperature of 39.9°F (4.4°C) in May, indicating a substantial decrease from the day's temperature.

Humidity

In May, the average relative humidity is 71%.

Rainfall

In Lewiston, in May, it is raining for 11.5 days, with typically 2.2" (56mm) of accumulated precipitation. Throughout the year, there are 119.2 rainfall days, and 33.35" (847mm) of precipitation is accumulated.

Snowfall

In Lewiston, snow does not fall in May through October.

Daylight

In Lewiston, the average length of the day in May is 14h and 28min.
On the first day of the month, sunrise is at 6:08 am and sunset at 8:07 pm. On the last day of May, sunrise is at 5:42 am and sunset at 8:35 pm PDT.

Sunshine

In May, the average sunshine is 10.1h.

UV index

In Lewiston, California, the average daily maximum UV index in May is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.
Note: The maximum UV index of 4 during May leads to these instructions:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.
Updated: Aug 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in May in Lewiston?

The average high-temperature, in May, in Lewiston, is 64.9°F (18.3°C), while the average low-temperature is 39.9°F (4.4°C).

What is the average humidity in May?

In Lewiston, the average relative humidity in May is 71%.

How many days does it rain in May?

In Lewiston, in May, it is raining for 11.5 days, with typically 2.2" (56mm) of accumulated precipitation.

When it does not snow?

May through October are months without snowfall.

Does it snow in May?

In May, it doesn't snow. April is the latest month when it typically snows.

What is the average length of the day in May?

The average day length in May is 14h and 28min.

What time are sunrise and sunset in May?

On the first day of May, sunrise is at 6:08 am and sunset at 8:07 pm. On the last day of the month, sunrise is at 5:42 am and sunset at 8:35 pm PDT.

How many hours of sunshine does Lewiston have in May?

The average sunshine duration in May is 10.1h.

What is the UV index intensity in May?

In Lewiston, the average daily maximum UV index in May is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
Lewiston, CA

Average temperature in May - Lewiston, CA
  • Average high temperature in May: 64.9°F

The warmest months (with the highest average high temperature) are July and August (84.6°F).
The month with the lowest average high temperature is December (45°F).

  • Average low temperature in May: 39.9°F

The month with the highest average low temperature is July (51.3°F).
The coldest month (with the lowest average low temperature) is December (30°F).

Average pressure in May
Lewiston, CA

Average pressure in May - Lewiston, CA
  • Average pressure in May: 29.99"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.94"Hg).

Average wind speed in May
Lewiston, CA

Average wind speed in May - Lewiston, CA
  • Average wind speed in May: 4.3mph

The windiest months (with the highest average wind speed) are March and April (4.8mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).

Average humidity in May
Lewiston, CA

Average humidity in May - Lewiston, CA
  • Average humidity in May: 71%

The month with the highest relative humidity is March (82%).
The month with the lowest relative humidity is August (54%).

Average rainfall in May
Lewiston, CA

Average rainfall in May - Lewiston, CA
  • Average rainfall in May: 2.2"

The wettest month (with the highest rainfall) is December (6.14").
The driest months (with the least rainfall) are July and August (0.16").

Average rainfall days in May
Lewiston, CA

Average rainfall days in May - Lewiston, CA
  • Average rainfall days in May: 11.5 days

The month with the highest number of rainy days is March (18.3 days).
The month with the least rainy days is August (2.5 days).

Average snowfall in May
Lewiston, CA

Average snowfall in May - Lewiston, CA
  • Average snowfall in May: 0"

The month with the highest snowfall is February (8.35").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in May
Lewiston, CA

Average snowfall days in May - Lewiston, CA
  • Average snowfall days in May: 0.1 days

The month with the highest number of snowfall days is February (5.3 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

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

Average daylight in May / Average sunshine in May - Lewiston, CA
  • Average daylight in May: 14h and 3min

The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in May: 10h and 1min

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).

Average sunshine days in May
Lewiston, CA

Average sunshine days in May - Lewiston, CA
  • Average sunshine days in May: 17.3 days

The month with the most sunshine days is August (26.8 days).
The month with the least sunshine days is March (10.6 days).

Average UV index in May
Lewiston, CA

Average UV index in May - Lewiston, CA
  • Average UV index in May: 4

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in May
Lewiston, CA

Average cloud cover in May - Lewiston, CA
  • Average cloud cover in May: 34

The month with the most cloud cover is March (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 8).

Average visibility in May
Lewiston, CA

Average visibility in May - Lewiston, CA
  • Average visibility in May: 5mi

The months with the highest visibility are June, July, August, September and October (6mi).
The months with the lowest visibility are March and December (4mi).

Lewiston, California, USA

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