Weather in Jefferson County

Calculated from weather data of Grenadier Island (CWGH) between 2020 and 2024.

Maximum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	30.0	31.0	33.0	25.0	30.0	32.0
February	34.0	39.0	36.0	33.0	30.0	33.0
March	43.0	46.0	39.0	41.0	45.0	44.0
April	54.0		57.0	54.0	56.0	50.0
May	66.0		66.0	70.0	66.0	64.0
June	75.0		74.0	74.0	78.0	77.0
July	80.0		81.0	80.0	77.0	84.0
August	79.0		76.0	81.0	82.0	79.0
September	71.0		73.0	70.0	72.0	70.0
October	61.0		61.0	61.0	63.0	58.0
November	46.0		45.0	49.0	46.0	51.0
December	37.0		40.0	36.0	39.0	36.0
Average	54.0	39.0	57.0	57.0	57.0	57.0

48th highest temperature of Canada

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	18.0	21	23	6	20	21
February	19.0	25	19	14	16	19
March	28.0	32	28	26	26	30
April	38.0		39	37	39	35
May	47.0		46	50	47	45
June	58.0		56	57	60	57
July	64.0		64	63	61	67
August	63.0		61	64	66	62
September	56.0		57	55	57	54
October	46.0		49	44	50	43
November	34.0		32	37	34	38
December	26.0		30	28	27	26
Average	40.0	26.0	42.0	41.0	42.0	42.0

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	5	10	9	17
77 °F or warmer	0	67	72	71	80
68 °F or warmer	0	134	135	137	120
32 °F or colder	63	116	114	120	125

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	0.0	0	0	0	0	0
February	0.0	0	0	0	0	0
March	0.0	0	0	0	0	0
April	0.0		0	0	0	0
May	0.0		0	0	0	0
June	0.0		0	0	0	0
July	0.0		0	0	0	0
August	0.0		0	0	0	0
September	0.0		0	0	0	0
October	0.0		0	0	0	0
November	0.0		0	0	0	0
December	0.0		0	0	0	0
Average

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	4.2	4	4	5	4	4
February	5.3	5	5	7	5	6
March	4.8	5	5	4	5	6
April	4.9		5	5	4	6
May	3.8		4	4	4	4
June	3.0		2	3	4	3
July	2.9		3	3	3	3
August	2.8		3	3	3	3
September	3.0		3	3	3	4
October	4.0		3	4	4	5
November	5.0		4	5	4	5
December	5.2		4	6	5	6
Average	4.1	4.6	3.5	4.0	3.8	4.4

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

Prevailing wind direction

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

Jefferson County weather Q&A

What is the warmest month in Jefferson County?

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

What is the coldest month in Jefferson County?

The coldest month is January with an average daytime temperature of 30 °F in the past few years.

Which month is the wettest in Jefferson County?

Chance of precipitation is the highest in January with a probability of around 0.0 %.

Which month is the driest in Jefferson County?

The least rainfall and snow can be expected in January. The probability is about 0.0 %.