Weather in St. Lawrence County

Calculated from weather data of Massena International-Richards Field (KMSS) between 2020 and 2024.

Maximum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	27.0	29.0	30.0	21.0	27.0	31.0
February	32.0	37.0	32.0	30.0	27.0	31.0
March	39.0	45.0	37.0	40.0	45.0	43.0
April	54.0	56.0	58.0	54.0	57.0	50.0
May	67.0		67.0	71.0	67.0	65.0
June	76.0		75.0	74.0	79.0	78.0
July	81.0		81.0	79.0	76.0	86.0
August	79.0		75.0	79.0	80.0	78.0
September	72.0		73.0	69.0	70.0	69.0
October	60.0		61.0	62.0	61.0	57.0
November	44.0		43.0	48.0	44.0	50.0
December	33.0		37.0	35.0	36.0	34.0
Average	54.0	42.0	56.0	56.0	56.0	57.0

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	12.0	19	19	-5	13	17
February	13.0	19	12	6	8	12
March	23.0	27	24	22	22	28
April	35.0	36	37	36	37	31
May	46.0		43	47	45	43
June	55.0		54	55	58	55
July	61.0		62	60	58	64
August	59.0		57	60	60	58
September	51.0		52	51	50	47
October	41.0		45	36	45	38
November	28.0		28	32	28	32
December	19.0		26	23	20	25
Average	36.0	25.0	39.0	36.0	37.0	38.0

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	8	10	23
77 °F or warmer	0	64	62	63	76
68 °F or warmer	3	134	130	133	120
32 °F or colder	84	131	131	134	136

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	22.1	28	33	21	12	19
February	21.4	14	35	30	19	18
March	19.3	19	30	27	8	15
April	17.8	28	19	18	13	13
May	10.4		10	16	4	4
June	8.7		7	11	8	4
July	5.9		8	7	8	4
August	6.0		7	6	4	11
September	6.3		4	11	7	5
October	13.5		22	10	14	13
November	14.8		10	17	15	11
December	21.9		29	28	11	20
Average	14.0	22.6	16.8	15.6	9.5	10.0

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	8.9	9	7	8	8	9
February	10.3	9	10	12	8	11
March	10.2	10	9	11	11	11
April	10.7	11	11	11	10	11
May	8.8		9	8	9	9
June	8.0		6	8	9	8
July	7.5		6	9	7	8
August	6.8		6	7	6	7
September	6.9		6	7	6	8
October	8.4		8	8	8	9
November	9.4		9	9	8	11
December	8.8		8	10	10	10
Average	8.8	9.7	7.8	8.7	8.3	9.0

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	NW	W	W	SW
February	W	W	W	W	W
March	W	NW	W	W	W
April	N	SW	W	NW	W
May		W	NW	W	W
June		N	SW	SW	SW
July		SW	SW	W	SW
August		SW	SW	SW	W
September		W	W	W	SW
October		SW	SW	NE	SW
November		SW	SW	SW	SW
December		N	SE	W	W

Prevailing wind direction

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

St. Lawrence County weather Q&A

What is the warmest month in St. Lawrence County?

The warmest month is July with an average temperature of 81 °F over the past years.

What is the coldest month in St. Lawrence County?

The coldest month is January with an average daytime temperature of 27 °F in the past few years.

Which month is the wettest in St. Lawrence County?

Chance of precipitation is the highest in January with a probability of around 22.1 %.

Which month is the driest in St. Lawrence County?

The least rainfall and snow can be expected in July. The probability is about 5.9 %.