May weather forecastHillsboro, OR
May
Weather in May
May in Hillsboro sees a marked decrease in cloud cover and allows residents to enjoy the sun for an average of 8.3 hours a day. The warmth signifies the transition from spring to summer, driving greenery to flourish, contrasting beautifully with the clear blue skies. The temperature begins to swim in the higher ranges, with warm days that can peak at nearly 67.1°F (19.5°C). It... a sharp decrease in the number of rainy days, making hikes and picnics more frequent and enjoyable affairs. Although the air retains a slight chill, the month concludes Hillsboro's spring with increasing dryness in contrast to the preceding wet months.Temperature
Hillsboro's weather in May presents a minor rise in the average high-temperature, moving from a moderate 58.3°F (14.6°C) in April to a comfortable 67.1°F (19.5°C). May nights see a notable contrast from daytime highs, with the nighttime temperature averaging at a chilly 44.4°F (6.9°C).Humidity
In May, the average relative humidity is 73%.Rainfall
In Hillsboro, during May, the rain falls for 13.6 days and regularly aggregates up to 1.73" (44mm) of precipitation. In Hillsboro, Oregon, during the entire year, the rain falls for 173 days and collects up to 29.49" (749mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In Hillsboro, the average length of the day in May is 14h and 56min.On the first day of the month, sunrise is at 5:58 am and sunset at 8:19 pm. On the last day of May, sunrise is at 5:26 am and sunset at 8:53 pm PDT.
Sunshine
In May, the average sunshine is 8.3h.UV index
In May, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.Note: The average daily UV index of 4 in May transforms into the following instructions:
Heed the precautions - Suggestions to avoid sunburn are made. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Hillsboro, OR
- Average high temperature in May: 67.1°F
The warmest month (with the highest average high temperature) is August (81.5°F).
The month with the lowest average high temperature is December (43.9°F).
- Average low temperature in May: 44.4°F
The month with the highest average low temperature is August (55.4°F).
The coldest month (with the lowest average low temperature) is December (34°F).
Average pressure in May
Hillsboro, OR
- Average pressure in May: 30.04"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in May
Hillsboro, OR
- Average wind speed in May: 4.4mph
The windiest month (with the highest average wind speed) is March (5mph).
The calmest months (with the lowest average wind speed) are June, August and September (4.3mph).
Average humidity in May
Hillsboro, OR
- Average humidity in May: 73%
The months with the highest relative humidity are January, February, November and December (85%).
The month with the lowest relative humidity is August (64%).
Average rainfall in May
Hillsboro, OR
- Average rainfall in May: 1.73"
The wettest month (with the highest rainfall) is January (4.57").
The driest month (with the least rainfall) is August (0.31").
Average rainfall days in May
Hillsboro, OR
- Average rainfall days in May: 13.6 days
The month with the highest number of rainy days is March (20.8 days).
The month with the least rainy days is August (4.4 days).
Average snowfall in May
Hillsboro, OR
- Average snowfall in May: 0"
The month with the highest snowfall is February (1.81").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in May
Hillsboro, OR
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is February (2.4 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in May /
Average sunshine in May
Hillsboro, OR
- Average daylight in May: 14h and 54min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in May: 8h and 18min
The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 3h and 42min).
Average sunshine days in May
Hillsboro, OR
- Average sunshine days in May: 16.2 days
The month with the most sunshine days is July (24.4 days).
The month with the least sunshine days is March (8.5 days).
Average UV index in May
Hillsboro, OR
- 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
Hillsboro, OR
- Average cloud cover in May: 49
The month with the most cloud cover is February (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in May
Hillsboro, OR
- Average visibility in May: 5mi
The months with the highest visibility are July, August and September (6mi).
The months with the lowest visibility are January and February (4mi).
