Weather in Ada County

Calculated from weather data of Boise Air Terminal/Gowen Field (KBOI) between 2020 and 2024.

Maximum temperatures (°F)

Month	Average	2024	2023	2022	2021	2020
January	40.0	41.0	41.0	35.0	43.0	44.0
February	45.0	51.0	45.0	44.0	43.0	48.0
March	55.0	55.0	48.0	58.0	58.0	56.0
April	63.0	64.0	62.0	59.0	66.0	65.0
May	74.0		78.0	69.0	74.0	74.0
June	84.0		81.0	82.0	92.0	80.0
July	96.0		98.0	97.0	99.0	92.0
August	93.0		92.0	98.0	90.0	93.0
September	82.0		82.0	87.0	83.0	84.0
October	65.0		68.0	69.0	66.0	68.0
November	50.0		52.0	42.0	53.0	49.0
December	39.0		42.0	33.0	42.0	40.0
Average	64.0	53.0	66.0	65.0	67.0	66.0

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	27.0	27	28	24	30	32
February	29.0	35	26	23	29	29
March	35.0	35	31	36	33	36
April	40.0	41	39	36	40	41
May	49.0		53	45	47	49
June	56.0		56	55	62	55
July	65.0		66	67	70	60
August	63.0		63	67	62	64
September	54.0		56	58	53	55
October	42.0		46	44	45	43
November	33.0		35	28	37	33
December	28.0		31	24	29	26
Average	42.0	35.0	44.0	43.0	45.0	44.0

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	77	84	84	82
77 °F or warmer	3	139	115	134	127
68 °F or warmer	15	173	166	166	168
32 °F or colder	34	97	111	80	87

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	9.2	18	5	6	7	10
February	8.9	14	2	5	10	9
March	7.0	11	14	1	3	8
April	5.6	5	5	10	2	2
May	3.6		1	6	2	5
June	2.8		1	6	2	8
July	0.1		0	0	0	0
August	0.2		1	0	1	0
September	1.7		3	1	1	0
October	3.8		8	1	6	1
November	5.3		5	10	3	10
December	8.9		7	22	13	8
Average	5.2	11.7	4.2	5.1	3.6	4.6

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	7.4	7	9	7	8	8
February	9.3	9	10	8	10	9
March	9.4	8	11	10	9	8
April	9.9	9	11	11	8	9
May	8.5		8	10	10	9
June	8.0		7	8	8	8
July	7.3		7	8	7	8
August	7.2		7	7	8	8
September	7.2		7	7	8	8
October	7.4		7	7	9	8
November	7.1		6	8	7	8
December	7.0		6	6	8	7
Average	8.1	8.5	7.9	7.9	8.3	8.0

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

Prevailing wind direction

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

Ada County weather Q&A

What is the warmest month in Ada County?

The warmest month is July with an average temperature of 96 °F over the past years.

What is the coldest month in Ada County?

The coldest month is December with an average daytime temperature of 39 °F in the past few years.

Which month is the wettest in Ada County?

Chance of precipitation is the highest in January with a probability of around 9.2 %.

Which month is the driest in Ada County?

The least rainfall and snow can be expected in July. The probability is about 0.2 %.