What is the hottest month in Lewiston?

July is the warmest month in Lewiston, with an average high of 90.8°F.

What is the coldest month in Lewiston?

December is the coldest month in Lewiston, with an average low of 29.5°F.

What month does Lewiston get the most rain?

May is typically the wettest month in Lewiston, with about 1.69 inches of precipitation.

What plant hardiness zone is Lewiston in?

Lewiston is approximately in USDA plant hardiness Zone 8a, based on the average annual extreme minimum temperature.

Lewiston, ID

Climate overview — based on NOAA 1991-2020 normals from LEWISTON NEZ PERCE CO AP, ID US.

BSk Semi-arid (cold) climate 8a USDA hardiness Zone 8a

Year-round temperatures (°F)

Avg high Avg low

Climate summary

Lewiston has an annual average temperature of 53.8°F with about 12.9 inches of precipitation per year and 12.7 inches of snow. The warmest month is July (average high 90.8°F), and the coldest is December (average low 29.5°F). May is typically the wettest month (1.69 in) and July the driest (0.47 in). Snow typically falls from November through March.

Pleasant months

2 / 12

avg high 65–80°F, low ≥ 50°F

Annual swing

40.6°F

warmest to coldest month

Heating need

4,749

HDD/yr

Cooling need

702

CDD/yr

Best time to visit Lewiston

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Monthly averages

Month	Avg High	Avg Low	Avg Temp	Precipitation	Snow	Rainy days
January	42.1°F	30.3°F	36.2°F	1.13 in	2.7 in	11
February	47.0°F	31.7°F	39.3°F	1.04 in	3.8 in	10
March	55.1°F	35.7°F	45.4°F	1.30 in	0.8 in	12
April	62.3°F	40.7°F	51.5°F	1.44 in	—	11
May	72.0°F	48.1°F	60.0°F	1.69 in	—	11
June	79.0°F	54.0°F	66.5°F	1.25 in	—	9
July	90.8°F	60.9°F	75.8°F	0.47 in	—	4
August	90.1°F	60.3°F	75.2°F	0.51 in	—	3
September	79.5°F	52.3°F	65.9°F	0.60 in	—	5
October	63.0°F	42.0°F	52.5°F	1.08 in	—	9
November	48.7°F	34.5°F	41.6°F	1.23 in	1.3 in	11
December	40.8°F	29.5°F	35.2°F	1.13 in	4.1 in	11