Weather in San Juan County

Calculated from weather data of Friday Harbor Airport (KFHR) between 2019 and 2022.

Maximum temperatures (°F)

Month	Average	2022	2021	2020	2019
January	46.0	45.0	47.0	47.0	49.0
February	45.0	47.0	44.0	46.0	42.0
March	51.0	52.0	50.0	49.0	54.0
April	57.0	54.0	58.0	58.0	60.0
May	64.0	59.0	61.0	65.0	68.0
June	69.0	67.0	72.0	65.0	73.0
July	73.0	73.0	73.0	71.0	70.0
August	74.0	76.0	73.0	73.0	74.0
September	68.0	70.0	66.0	70.0	66.0
October	58.0	63.0	56.0	57.0	55.0
November	50.0	47.0	51.0	49.0	50.0
December	45.0	41.0	41.0	47.0	46.0
Average	58.0	58.0	58.0	58.0	59.0

1,964th highest temperature of United States

Average highest temperature per day

The maximum temperature is typically observed some hours after noon.

Minimum temperatures (°F)

Month	Average	2022	2021	2020	2019
January	38.0	37	40	39	39
February	35.0	37	36	37	31
March	38.0	40	38	36	37
April	42.0	40	41	41	44
May	46.0	44	45	45	49
June	49.0	49	50	50	49
July	51.0	51	51	51	52
August	52.0	50	53	51	53
September	51.0	49	50	52	51
October	45.0	47	45	46	43
November	41.0	36	43	41	40
December	37.0	34	33	39	40
Average	44.0	43.0	44.0	44.0	44.0

1,082nd lowest temperature of United States

Average lowest temperature per day

The minimum temperature is typically observed just before sunrise.

Cold and hot days

Number of days	2022	2021	2020	2019
86 °F or warmer	1	6	2	3
77 °F or warmer	24	18	15	17
68 °F or warmer	92	78	77	91
32 °F or colder	24	18	19	25

Precipitation (%)

Month	Average	2022	2021	2020	2019
January	12.6	8	16	21	6
February	13.9	10	14	13	11
March	7.8	12	6	4	1
April	8.9	7	6	6	10
May	6.9	11	4	9	5
June	5.6	7	3	8	2
July	2.0	3	0	5	4
August	1.5	0	3	2	4
September	6.9	0	12	8	6
October	10.4	10	14	6	13
November	14.5	8	28	17	5
December	12.4	9	7	13	17
Average	8.1	6.9	8.4	8.7	6.5

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	2022	2021	2020	2019
January	7.6	6	8	9	6
February	7.3	7	7	6	9
March	6.9	7	7	7	6
April	7.2	8	6	6	7
May	5.8	6	6	6	6
June	6.1	6	6	6	7
July	5.7	5	6	6	6
August	5.6	6	6	6	6
September	5.3	6	6	5	5
October	6.1	6	7	6	6
November	7.0	6	7	7	6
December	6.7	7	7	7	6
Average	6.4	6.1	6.4	6.3	6.1

2,027th highest wind speed of United States

Prevailing wind direction

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

Prevailing wind direction

Month	2022	2021	2020	2019
January	SE	SE	SE	E
February	E	SE	SE	NE
March	E	SE	E	NE
April	SE	SE	E	SE
May	S	S	S	SE
June	SE	S	S	S
July	SE	S	S	S
August	SE	S	SE	SE
September	E	SE	SE	SE
October	SE	SE	S	SE
November	NE	SE	SE	NE
December	E	E	SE	SE

Prevailing wind direction

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

San Juan County weather Q&A

What is the warmest month in San Juan County?

The warmest month is August with an average temperature of 74 °F over the past years.

What is the coldest month in San Juan County?

The coldest month is December with an average daytime temperature of 45 °F in the past few years.

Which month is the wettest in San Juan County?

Chance of precipitation is the highest in November with a probability of around 14.5 %.

Which month is the driest in San Juan County?

The least rainfall and snow can be expected in August. The probability is about 1.6 %.