Weather in Cowlitz County

Calculated from weather data of Southwest Washington Regional Airport (KKLS) between 2020 and 2024.

Maximum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	48.0	46.0	49.0	47.0	49.0	49.0
February	48.0	53.0	47.0	51.0	46.0	51.0
March	55.0	57.0	53.0	57.0	56.0	54.0
April	61.0		59.0	57.0	67.0	64.0
May	69.0		74.0	64.0	68.0	70.0
June	74.0		76.0	73.0	79.0	72.0
July	81.0		83.0	82.0	81.0	78.0
August	82.0		85.0	85.0	80.0	81.0
September	76.0		76.0	79.0	75.0	77.0
October	64.0		66.0	70.0	60.0	63.0
November	52.0		53.0	49.0	54.0	51.0
December	47.0		50.0	43.0	44.0	48.0
Average	62.0	52.0	64.0	64.0	63.0	63.0

Average highest temperature per day

The maximum temperature is typically observed some hours after noon.

Minimum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	38.0	36	38	37	40	42
February	36.0	40	35	36	37	36
March	38.0	39	37	42	36	36
April	42.0		42	40	40	42
May	49.0		50	46	47	49
June	53.0		51	53	55	53
July	56.0		55	58	57	56
August	58.0		59	59	57	56
September	53.0		52	54	52	56
October	46.0		47	48	46	47
November	40.0		39	34	45	40
December	37.0		40	34	37	38
Average	45.0	38.0	46.0	45.0	46.0	46.0

Average lowest temperature per day

The minimum temperature is typically observed just before sunrise.

Cold and hot days

Number of days	2024	2023	2022	2021	2020
86 °F or warmer	0	30	30	21	22
77 °F or warmer	0	99	86	71	63
68 °F or warmer	5	148	137	131	134
32 °F or colder	13	30	37	30	27

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	21.7	38	2	23	18	46
February	21.9	27	0	15	39	27
March	20.8	26	3	20	19	23
April	18.0		0	25	7	9
May	9.8		0	21	10	15
June	7.4		0	8	12	14
July	2.2		0	1	0	6
August	2.9		5	1	3	1
September	7.7		7	2	7	6
October	13.8		15	10	17	8
November	22.2		15	23	26	25
December	25.0		28	17	35	23
Average	15.6	30.4	5.8	13.7	14.7	15.9

Precipitation during daylight period

Percentage of observations with observed rain, drizzle, snow or hail. Only observations between sunrise and sunset are taken into account.

Wind speed (miles per hour)

Month	Average	2024	2023	2022	2021	2020
January	6.8	7	6	7	6	9
February	6.3	6	7	6	7	6
March	6.3	7	7	6	6	5
April	6.1		7	6	5	5
May	5.4		6	6	6	5
June	5.5		7	5	5	5
July	5.4		6	5	5	5
August	5.4		6	6	5	6
September	5.3		6	5	5	5
October	5.5		5	6	7	5
November	6.1		5	6	7	7
December	6.5		6	6	7	7
Average	6.0	6.9	6.1	5.8	5.9	5.8

Average wind speed

Excluding wind gusts. Only observations between sunrise and sunset are taken into account.

Prevailing wind direction

Month	2024	2023	2022	2021	2020
January	SE	SE	SE	SE	S
February	S	S	S	S	S
March	S	S	S	S	S
April		S	S	W	SW
May		NW	SW	NW	SW
June		NW	W	NW	W
July		NW	NW	NW	NW
August		NW	NW	NW	NW
September		W	NW	SW	NW
October		S	W	S	SW
November		S	SE	S	S
December		SE	SE	SE	SE

Prevailing wind direction

Average wind direction, weighed by wind speed. Only observations between sunrise and sunset are taken into account.

Cowlitz County weather Q&A

What is the warmest month in Cowlitz County?

The warmest month is August with an average temperature of 82 °F over the past years.

What is the coldest month in Cowlitz County?

The coldest month is December with an average daytime temperature of 47 °F in the past few years.

Which month is the wettest in Cowlitz County?

Chance of precipitation is the highest in December with a probability of around 25.0 %.

Which month is the driest in Cowlitz County?

The least rainfall and snow can be expected in July. The probability is about 2.3 %.