Tri-Cities, WA Weather by Month and Climate Averages

How much rain does Tri-Cities get?

Tri-Cities gets 7.6 in of precipitation in an average year, spread over about 77 days with measurable rain. That is fewer rainy days than 61% of the US.

January is the wettest month, with 1.0 in. July is the driest, with 0.1 in. December has the most rainy days, about 10.

The longest dry spell in the last five years lasted 88 days, to August 15, 2025.

See where Tri-Cities ranks: rainiest cities in the US, US cities with the most rainy days, rainiest cities in Washington.

Tri-Cities weather by month

Tri-Cities weather in January

In January, Tri-Cities averages a high of 42°F and a low of 28°F. It gets 1.0 in of precipitation over about 10 rainy days. The sun is out about 25% of daylight hours. The January record high is 67°F (2002) and the record low is -19°F (2004).

Tri-Cities weather in February

In February, Tri-Cities averages a high of 49°F and a low of 29°F. It gets 0.6 in of precipitation over about 8 rainy days. The sun is out about 42% of daylight hours. The February record high is 69°F (2022) and the record low is -2°F (2019).

Tri-Cities weather in March

In March, Tri-Cities averages a high of 59°F and a low of 33°F. It gets 0.7 in of precipitation over about 8 rainy days. The sun is out about 44% of daylight hours. The March record high is 80°F (2024) and the record low is -1°F (2019).

Tri-Cities weather in April

In April, Tri-Cities averages a high of 67°F and a low of 39°F. It gets 0.7 in of precipitation over about 7 rainy days. The sun is out about 48% of daylight hours. The April record high is 94°F (1998) and the record low is 21°F (2008). April is one of the most comfortable months to visit.

Tri-Cities weather in May

In May, Tri-Cities averages a high of 76°F and a low of 46°F. It gets 0.7 in of precipitation over about 7 rainy days. The sun is out about 51% of daylight hours. The May record high is 101°F (2001) and the record low is 28°F (2013). May is one of the most comfortable months to visit.

Tri-Cities weather in June

In June, Tri-Cities averages a high of 84°F and a low of 53°F. It gets 0.6 in of precipitation over about 5 rainy days. The sun is out about 58% of daylight hours. The June record high is 115°F (2021) and the record low is 37°F (2002).

Tri-Cities weather in July

In July, Tri-Cities averages a high of 93°F and a low of 57°F. It gets 0.1 in of precipitation over about 2 rainy days. The sun is out about 87% of daylight hours. The July record high is 112°F (2006) and the record low is 42°F (1999).

Tri-Cities weather in August

In August, Tri-Cities averages a high of 91°F and a low of 56°F. It gets 0.3 in of precipitation over about 2 rainy days. The sun is out about 73% of daylight hours. The August record high is 111°F (1998) and the record low is 40°F (2008).

Tri-Cities weather in September

In September, Tri-Cities averages a high of 81°F and a low of 48°F. It gets 0.3 in of precipitation over about 3 rainy days. The sun is out about 65% of daylight hours. The September record high is 102°F (2022) and the record low is 26°F (2000).

Tri-Cities weather in October

In October, Tri-Cities averages a high of 66°F and a low of 39°F. It gets 0.7 in of precipitation over about 6 rainy days. The sun is out about 58% of daylight hours. The October record high is 90°F (2020) and the record low is 9°F (2002). October is one of the most comfortable months to visit.

Tri-Cities weather in November

In November, Tri-Cities averages a high of 51°F and a low of 32°F. It gets 0.9 in of precipitation over about 9 rainy days. The sun is out about 34% of daylight hours. The November record high is 77°F (1999) and the record low is -7°F (2010).

Tri-Cities weather in December

In December, Tri-Cities averages a high of 41°F and a low of 27°F. It gets 1.0 in of precipitation over about 10 rainy days. The sun is out about 23% of daylight hours. The December record high is 71°F (2021) and the record low is -9°F (2016).

Sunshine, humidity and wind in Tri-Cities

July is the sunniest month in Tri-Cities, with sunshine about 87% of daylight hours. December is the cloudiest, at 23%. Over the year the sun shines about 51% of daylight hours. Tri-Cities is sunnier than 64% of the US.

Humidity peaks in December at 79% and is lowest in July at 24%.

Wind averages 6 mph over the year, and April is the windiest month at 8 mph.

Tri-Cities has about 57 days a year above 90°F. Tri-Cities is hotter than 73% of the US.

Thunderstorms occur on about 6 days a year.

See where Tri-Cities ranks: sunniest cities in the US, cloudiest cities in the US, hottest cities in the US.

First and last freeze in Tri-Cities

The first fall freeze in Tri-Cities typically comes around October 13, and the last spring freeze around April 30. That leaves a frost-free growing season of about 166 days.

Tri-Cities weather records

The hottest temperature on record at the Tri-Cities station is 115°F, on June 27, 2021. The coldest is -19°F, on January 4, 2004.

The wettest day on record brought 1.1 in of rain, on June 1, 2011.

The best time to visit Tri-Cities

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

Winter (December–February) is chilly, with average highs around 44°F and lows near 28°F.

Spring (March–May) is mild, with average highs around 68°F and lows near 39°F.

Summer (June–August) is hot, with average highs around 89°F and lows near 55°F.

Autumn (September–November) is mild, with average highs around 66°F and lows near 39°F.

Tri-Cities climate questions

How much rain does Tri-Cities get?

Tri-Cities gets 7.6 in of precipitation in an average year, over about 77 rainy days.

What is the wettest month in Tri-Cities?

January is the wettest month in Tri-Cities, with 1.0 in. July is the driest, with 0.1 in.

How many rainy days does Tri-Cities have a year?

Tri-Cities has about 77 days with measurable rain in an average year. December has the most, about 10.

What is the hottest month in Tri-Cities?

July is the warmest month in Tri-Cities, with an average high of 93°F.

What is the coldest month in Tri-Cities?

December is the coldest month in Tri-Cities, with an average low of 27°F.

What is the record high temperature in Tri-Cities?

The record high at the Tri-Cities station is 115°F, set on June 27, 2021. The record low is -19°F, on January 4, 2004.

What is the sunniest month in Tri-Cities?

July is the sunniest month in Tri-Cities, with sunshine about 87% of daylight hours. December is the cloudiest.

When is the first frost in Tri-Cities?

The first fall freeze in Tri-Cities typically comes around October 13. The last spring freeze is around April 30.

What is the best time to visit Tri-Cities?

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