Hillsboro, OR Weather by Month and Climate Averages

How much rain does Hillsboro get?

Hillsboro gets 35.9 in of precipitation in an average year, spread over about 158 days with measurable rain. That is more rainy days than 96% of the US.

December is the wettest month, with 6.0 in. July is the driest, with 0.4 in. December has the most rainy days, about 20.

The longest dry spell in the last five years lasted 65 days, to September 10, 2022.

See where Hillsboro ranks: rainiest cities in the US, US cities with the most rainy days, rainiest cities in Oregon.

Hillsboro weather by month

Hillsboro weather in January

In January, Hillsboro averages a high of 47°F and a low of 34°F. It gets 5.3 in of precipitation over about 19 rainy days. The sun is out about 16% of daylight hours. The January record high is 64°F (2005) and the record low is 3°F (2017).

Hillsboro weather in February

In February, Hillsboro averages a high of 50°F and a low of 34°F. It gets 4.0 in of precipitation over about 16 rainy days. The sun is out about 27% of daylight hours. The February record high is 66°F (2022) and the record low is 16°F (2006).

Hillsboro weather in March

In March, Hillsboro averages a high of 55°F and a low of 36°F. It gets 3.7 in of precipitation over about 18 rainy days. The sun is out about 31% of daylight hours. The March record high is 79°F (2025) and the record low is 20°F (2019).

Hillsboro weather in April

In April, Hillsboro averages a high of 61°F and a low of 39°F. It gets 2.6 in of precipitation over about 16 rainy days. The sun is out about 36% of daylight hours. The April record high is 90°F (2023) and the record low is 25°F (2008).

Hillsboro weather in May

In May, Hillsboro averages a high of 68°F and a low of 45°F. It gets 2.0 in of precipitation over about 12 rainy days. The sun is out about 38% of daylight hours. The May record high is 94°F (2006) and the record low is 30°F (2013). May is one of the most comfortable months to visit.

Hillsboro weather in June

In June, Hillsboro averages a high of 73°F and a low of 49°F. It gets 1.3 in of precipitation over about 9 rainy days. The sun is out about 51% of daylight hours. The June record high is 114°F (2021) and the record low is 35°F (2001). June is one of the most comfortable months to visit.

Hillsboro weather in July

In July, Hillsboro averages a high of 82°F and a low of 52°F. It gets 0.4 in of precipitation over about 3 rainy days. The sun is out about 75% of daylight hours. The July record high is 108°F (2006) and the record low is 39°F (2000).

Hillsboro weather in August

In August, Hillsboro averages a high of 82°F and a low of 52°F. It gets 0.5 in of precipitation over about 4 rainy days. The sun is out about 66% of daylight hours. The August record high is 107°F (2023) and the record low is 38°F (2008).

Hillsboro weather in September

In September, Hillsboro averages a high of 76°F and a low of 48°F. It gets 1.4 in of precipitation over about 8 rainy days. The sun is out about 55% of daylight hours. The September record high is 100°F (2017) and the record low is 30°F (1999). September is one of the most comfortable months to visit.

Hillsboro weather in October

In October, Hillsboro averages a high of 63°F and a low of 42°F. It gets 3.4 in of precipitation over about 15 rainy days. The sun is out about 44% of daylight hours. The October record high is 89°F (2022) and the record low is 20°F (2002). October is one of the most comfortable months to visit.

Hillsboro weather in November

In November, Hillsboro averages a high of 52°F and a low of 37°F. It gets 5.4 in of precipitation over about 19 rainy days. The sun is out about 27% of daylight hours. The November record high is 70°F (2010) and the record low is 15°F (2010).

Hillsboro weather in December

In December, Hillsboro averages a high of 46°F and a low of 33°F. It gets 6.0 in of precipitation over about 20 rainy days. The sun is out about 20% of daylight hours. The December record high is 63°F (2023) and the record low is 4°F (1998).

Sunshine, humidity and wind in Hillsboro

July is the sunniest month in Hillsboro, with sunshine about 75% of daylight hours. January is the cloudiest, at 16%. Over the year the sun shines about 41% of daylight hours. Hillsboro is cloudier than 86% of the US.

Humidity peaks in December at 86% and is lowest in July at 52%.

Wind averages 5 mph over the year, and March is the windiest month at 5 mph.

Hillsboro has about 19 days a year above 90°F. Hillsboro is cooler than 63% of the US.

Thunderstorms occur on about 4 days a year.

See where Hillsboro ranks: sunniest cities in the US, cloudiest cities in the US, hottest cities in the US.

First and last freeze in Hillsboro

The first fall freeze in Hillsboro typically comes around October 25, and the last spring freeze around April 20. That leaves a frost-free growing season of about 188 days.

Hillsboro weather records

The hottest temperature on record at the Hillsboro station is 114°F, on June 28, 2021. The coldest is 3°F, on January 13, 2017.

The wettest day on record brought 2.6 in of rain, on January 1, 2009.

The best time to visit Hillsboro

The most comfortable time to visit is typically May to June and September to October, when daytime highs sit near 70°F.

Winter (December–February) is chilly, with average highs around 48°F and lows near 34°F.

Spring (March–May) is mild, with average highs around 61°F and lows near 40°F.

Summer (June–August) is warm, with average highs around 79°F and lows near 51°F.

Autumn (September–November) is mild, with average highs around 64°F and lows near 42°F.

Hillsboro climate questions

How much rain does Hillsboro get?

Hillsboro gets 35.9 in of precipitation in an average year, over about 158 rainy days.

What is the wettest month in Hillsboro?

December is the wettest month in Hillsboro, with 6.0 in. July is the driest, with 0.4 in.

How many rainy days does Hillsboro have a year?

Hillsboro has about 158 days with measurable rain in an average year. December has the most, about 20.

What is the hottest month in Hillsboro?

July is the warmest month in Hillsboro, with an average high of 82°F.

What is the coldest month in Hillsboro?

December is the coldest month in Hillsboro, with an average low of 33°F.

What is the record high temperature in Hillsboro?

The record high at the Hillsboro station is 114°F, set on June 28, 2021. The record low is 3°F, on January 13, 2017.

What is the sunniest month in Hillsboro?

July is the sunniest month in Hillsboro, with sunshine about 75% of daylight hours. January is the cloudiest.

When is the first frost in Hillsboro?

The first fall freeze in Hillsboro typically comes around October 25. The last spring freeze is around April 20.

What is the best time to visit Hillsboro?

The most comfortable time to visit is typically May to June and September to October, when daytime highs sit near 70°F.