Weather in King County

Calculated from weather data of Boeing Field/King County International (KBFI) between 2020 and 2024.

Maximum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	48.0	46.0	49.0	47.0	48.0	49.0
February	48.0	51.0	47.0	49.0	46.0	50.0
March	54.0	55.0	53.0	54.0	54.0	52.0
April	59.0		56.0	56.0	63.0	61.0
May	68.0		71.0	62.0	65.0	69.0
June	73.0		73.0	71.0	78.0	71.0
July	79.0		80.0	79.0	80.0	77.0
August	80.0		80.0	82.0	78.0	79.0
September	72.0		71.0	74.0	71.0	75.0
October	61.0		61.0	66.0	59.0	62.0
November	52.0		51.0	48.0	53.0	52.0
December	47.0		51.0	42.0	42.0	49.0
Average	61.0	51.0	62.0	61.0	62.0	62.0

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	37	38	37	39	41
February	37.0	40	36	38	37	38
March	39.0	42	38	42	38	38
April	44.0		43	41	43	44
May	51.0		53	47	49	52
June	55.0		52	55	58	55
July	59.0		58	60	59	59
August	60.0		61	61	59	59
September	56.0		53	56	55	58
October	47.0		46	50	47	49
November	41.0		39	36	44	40
December	38.0		40	35	35	38
Average	46.0	40.0	47.0	47.0	47.0	48.0

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	8	14	12	9
77 °F or warmer	0	61	51	60	54
68 °F or warmer	3	132	122	120	121
32 °F or colder	10	27	24	13	12

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	19.2	22	15	14	22	33
February	16.9	14	11	13	18	12
March	12.0	11	7	11	10	9
April	11.3		20	8	5	5
May	6.3		4	14	4	9
June	6.1		5	9	6	13
July	1.2		0	2	0	1
August	1.3		1	3	0	1
September	5.6		7	2	6	6
October	8.8		9	6	15	4
November	16.8		8	19	26	17
December	18.1		23	12	18	17
Average	10.3	15.4	8.7	9.0	9.8	9.9

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	5.7	5	5	5	5	8
February	6.5	6	7	6	8	6
March	6.5	6	7	6	7	7
April	7.1		8	7	6	6
May	5.6		5	6	6	6
June	5.6		5	5	6	6
July	5.3		5	5	5	6
August	5.5		5	6	6	5
September	5.7		5	6	6	5
October	5.8		5	5	7	6
November	5.8		4	5	7	7
December	5.3		4	4	7	6
Average	5.8	5.7	5.5	5.4	6.2	6.2

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	S	SE	S	SE	S
February	S	S	S	S	S
March	S	S	S	S	S
April		S	S	SW	SW
May		SW	S	SW	SW
June		SW	SW	SW	S
July		SW	W	W	SW
August		W	SW	SW	W
September		S	W	SW	SW
October		S	SW	S	S
November		S	S	S	S
December		SE	SE	S	S

Prevailing wind direction

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

King County weather Q&A

What is the warmest month in King County?

The warmest month is August with an average temperature of 80 °F over the past years.

What is the coldest month in King 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 King County?

Chance of precipitation is the highest in January with a probability of around 19.2 %.

Which month is the driest in King County?

The least rainfall and snow can be expected in July. The probability is about 1.3 %.