Humidity

Humidity Normals 1971-2000

Humidity measures the water vapor content of the air. It is often expressed as relative humidity:

the ratio of the actual vapor pressure of the air to the saturation vapor pressure for a given air temperature.

Another measure of humidity is dewpoint temperature:

the temperature to which a parcel of air must be cooled (at constant pressure and water vapor content) in order for saturation to occur.

View tabular humidity normals for selected stations for the period 1971-2000 below.

Mean monthly relative humidity (%), 1971 - 2000

Arctic		Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Barrow	Mean	75.2	73.5	73.7	79.3	87.1	87.6	87.3	89.8	89.8	85.7	80.4	76.5
	Max	88.3	87.1	85.9	91.3	95.5	96.0	96.5	97.9	98.0	95.2	92.4	89.1
	Min	64.6	61.5	64.3	69.0	76.2	73.4	72.1	77.0	76.9	73.5	68.6	65.9

Barter Island	Mean	71.9	68.9	66.3	73.2	86.0	89.9	89.8	91.6	90.8	84.5	76.8	73.2
	Max	86.2	84.0	80.1	88.7	95.1	97.3	98.3	99.1	98.8	94.8	88.6	87.4
	Min	58.5	54.7	51.8	58.2	74.4	79.2	75.0	78.4	76.2	70.1	62.4	59.0
Interior
Bettles	Mean	69.0	66.5	62.7	61.7	56.7	58.0	65.3	73.7	74.1	75.7	70.0	68.2
	Max	86.8	84.0	80.9	80.7	82.1	83.2	87.5	91.6	91.9	90.0	83.7	84.8
	Min	50.0	46.9	43.9	45.7	37.3	35.9	41.9	53.9	52.9	58.7	52.6	50.2

Big Delta	Mean	66.2	65.3	57.6	49.4	45.1	53.3	61.0	64.2	65.2	74.9	72.7	69.7
	Max	86.3	83.7	78.1	75.5	77.7	82.0	86.0	86.6	89.1	90.4	88.2	87.3
	Min	47.9	47.6	38.2	32.1	27.1	31.0	38.8	41.1	41.3	51.4	53.9	52.3

Fairbanks	Mean	72.1	69.2	62.2	54.4	49.4	56.9	64.7	71.9	71.0	75.4	74.6	73.8
	Max	85.9	84.0	80.1	75.7	75.8	83.5	87.5	90.5	90.2	90.5	87.0	86.8
	Min	54.9	53.0	44.7	38.6	30.9	34.8	42.7	50.9	49.2	54.2	60.9	57.1

McGrath	Mean	76.7	72.7	66.5	61.9	59.6	63.0	71.2	77.3	76.3	80.4	81.2	78.7
	Max	89.5	88.3	85.2	83.1	84.8	83.6	89.6	92.3	92.8	93.2	92.2	90.5
	Min	62.0	55.1	48.0	44.0	39.7	43.5	50.8	58.7	54.4	61.2	66.5	66.2
West
Bethel	Mean	77.4	74.1	78.0	79.0	74.9	75.1	80.2	84.6	83.5	83.4	82.5	78.4
	Max	93.3	91.7	93.4	93.7	92.5	92.4	94.1	96.4	95.3	96.2	95.0	93.5
	Min	59.7	56.5	60.4	63.5	56.3	55.9	61.8	68.0	67.4	66.4	65.2	62.2

Kotzebue	Mean	73.9	72.3	72.2	77.3	81.9	81.5	80.0	81.5	78.7	80.0	78.1	74.8
	Max	90.7	89.1	89.1	91.5	94.7	95.4	93.9	93.1	93.9	93.5	92.3	91.8
	Min	57.0	55.7	56.1	60.7	60.4	61.0	59.5	63.9	60.9	63.3	62.2	54.0

Nome	Mean	73.5	70.4	71.0	73.8	74.3	74.6	78.8	81.5	76.5	76.1	76.1	73.2
	Max	92.7	90.0	89.9	90.6	92.3	93.3	93.8	95.3	93.2	93.6	93.0	92.6
	Min	48.5	48.3	50.1	54.4	48.8	47.3	53.4	58.8	54.1	53.2	52.4	48.5
Southwest
Adak	Mean	77.1	76.4	77.1	74.7	76.8	80.0	82.8	83.6	79.7	76.0	75.9	76.8
	Max	89.5	89.9	90.1	87.8	88.6	89.9	91.4	91.5	90.5	87.9	89.5	90.4
	Min	62.7	61.1	61.6	59.8	61.8	67.8	70.8	70.1	65.8	61.9	62.0	62.6

Cold Bay	Mean	84.7	84.5	83.9	83.5	83.1	85.4	88.6	89.5	85.6	83.0	83.8	84.7
	Max	96.5	95.1	95.0	95.0	93.7	94.4	96.3	96.9	95.5	93.8	94.2	95.9
	Min	69.8	70.8	68.9	70.0	68.5	71.9	76.0	76.6	70.9	69.2	69.7	71.0

St. Paul	Mean	83.3	84.4	84.8	84.5	87.0	89.7	93.2	93.5	87.8	81.9	81.5	82.7
	Max	95.5	96.2	95.8	96.1	96.6	97.4	98.5	98.9	97.8	95.8	94.2	95.3
	Min	68.9	69.9	69.9	69.9	72.6	76.3	83.3	82.3	72.7	65.1	67.1	68.5
Bristol Bay
King Salmon	Mean	79.3	75.4	73.8	72.2	70.4	74.0	78.8	80.6	79.5	80.1	83.1	80.9
	Max	93.2	92.7	89.3	88.2	87.1	91.4	92.7	93.6	92.8	93.2	95.5	94.2
	Min	61.7	57.4	57.5	55.6	53.5	55.3	62.4	65.2	64.0	62.9	65.8	64.1
Cook Inlet
Anchorage	Mean	76.5	73.4	68.6	65.4	62.3	65.9	72.6	76.3	76.5	75.8	79.4	79.7
	Max	92.1	92.5	89.3	85.7	81.9	83.3	89.8	91.4	92.9	93.7	93.9	93.9
	Min	52.4	49.1	45.2	45.1	45.8	48.8	56.1	56.6	53.6	49.6	57.1	58.0

Homer	Mean	80.2	77.3	74.3	73.3	73.8	75.5	80.6	82.2	80.2	77.6	79.9	80.5
	Max	94.3	94.0	90.9	90.1	88.4	89.4	92.6	94.2	93.9	92.7	94.5	94.1
	Min	58.9	55.4	51.9	52.3	57.2	61.3	67.7	66.1	59.2	55.5	58.8	60.9

Talkeetna	Mean	72.7	69.9	67.1	63.7	63.8	67.4	73.8	79.8	80.7	79.1	76.4	76.2
	Max	94.4	94.6	93.5	89.5	89.3	91.3	94.5	97.0	97.7	98.2	95.4	95.2
	Min	46.7	45.7	44.0	43.0	40.8	46.2	50.9	56.0	55.1	49.7	50.9	50.8
Copper River Basin
Gulkana	Mean	71.3	68.3	61.2	55.3	50.4	53.2	60.6	64.2	66.2	75.0	77.1	74.6
	Max	86.9	87.1	83.7	77.9	76.1	83.4	85.1	88.2	89.2	91.6	90.5	89.6
	Min	54.1	47.0	41.4	40.9	33.7	33.0	40.4	46.3	46.3	49.6	58.6	55.7
Southcentral
Kodiak	Mean	78.8	77.1	74.2	76.2	78.3	82.1	84.5	81.4	80.2	75.3	76.3	77.4
	Max	95.9	96.0	94.9	95.1	96.2	97.1	97.6	96.8	96.3	95.4	94.2	95.0
	Min	51.5	50.2	45.2	47.2	50.5	54.4	60.2	57.2	53.1	46.9	48.7	50.4

Valdez	Mean	74.3	72.8	70.8	71.9	73.5	76.5	81.7	83.4	83.6	76.1	73.2	75.4
	Max	96.1	96.6	94.9	93.5	91.8	92.7	96.3	97.9	97.6	96.8	95.3	97.3
	Min	45.6	43.8	39.4	43.8	49.8	55.7	60.0	53.0	49.4	40.6	44.6	42.6

Yakutat	Mean	84.8	82.2	80.7	81.1	82.0	83.7	87.0	88.0	88.3	87.2	85.9	85.5
	Max	96.7	96.6	95.2	94.9	95.0	95.4	96.6	97.2	97.2	96.5	96.2	96.3
	Min	58.3	52.2	49.2	57.3	57.7	64.4	71.7	70.1	70.7	62.1	58.0	57.2
Southeast
Annette	Mean	79.8	77.6	77.1	75.6	75.7	77.7	80.2	82.2	84.1	84.0	81.7	82.0
	Max	95.0	94.9	94.0	92.3	92.3	93.4	95.0	95.7	96.6	95.7	95.2	95.8
	Min	47.8	44.8	44.3	45.5	52.5	58.7	61.3	63.4	61.6	57.7	49.5	49.5

Juneau	Mean	82.1	80.3	79.5	77.4	76.0	77.3	81.1	83.9	88.3	88.1	85.9	84.3
	Max	95.9	95.5	94.5	92.2	92.3	93.7	95.2	96.2	96.6	96.6	96.5	95.6
	Min	50.9	49.4	46.1	53.5	54.9	58.8	62.7	66.2	70.2	66.6	57.6	56.0

Mean monthly dewpoint temperature (°F), 1971 - 2000

Arctic		Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Barrow	Mean	-18.8	-21.4	-19.2	-5.0	17.3	31.1	36.3	35.6	28.4	11.4	-5.5	-15.8
	Max	6.4	3.7	2.7	15.8	30.4	40.1	46.7	45.6	39.0	27.7	16.9	7.7
	Min	-37.5	-40.1	-36.1	-23.2	1.5	23.5	29.8	27.1	17.2	-8.3	-25.8	-35.3

Barter Island	Mean	-19.1	-25.1	-24.1	-8.7	17.3	31.7	36.9	36.6	29.2	10.9	-7.6	-17.6
	Max	7.2	3.4	-1.8	15.3	30.4	39.2	46.1	45.2	37.7	26.1	12.9	9.9
	Min	-41.3	-46.2	-41.9	-30.9	1.9	25.6	31.2	28.4	18.4	-9.5	-30.1	-40.4
Interior
Bettles	Mean	-13.5	-15.8	-2.5	14.0	30.5	42.5	48.2	44.9	33.0	15.7	-7.8	-11.9
	Max	19.5	14.9	20.6	30.4	43.5	52.2	56.2	54.2	45.0	31.6	18.2	16.6
	Min	-42.9	-44.2	-26.6	-5.4	18.1	29.8	38.2	32.3	19.3	-3.8	-34.1	-41.4

Big Delta	Mean	-10.3	-6.1	3.7	16.5	28.0	40.4	47.1	43.3	33.3	18.0	-0.4	-5.2
	Max	15.3	17.9	21.6	28.5	39.3	49.7	54.1	52.0	43.9	32.4	19.5	18.6
	Min	-36.0	-30.8	-17.5	0.1	16.4	28.8	38.5	32.5	21.1	-0.1	-23.8	-31.9

Fairbanks	Mean	-13.5	-10.4	1.0	17.0	29.8	43.3	49.5	46.5	35.0	17.1	-3.0	-10.8
	Max	16.0	16.1	20.9	30.1	42.9	53.1	57.1	55.1	46.9	32.8	19.5	17.8
	Min	-38.8	-32.8	-20.1	-1.5	17.1	31.5	40.2	34.3	20.8	-3.2	-24.9	-35.7

McGrath	Mean	-10.0	-7.3	1.9	16.6	31.1	42.5	48.8	46.5	36.1	19.4	1.1	-8.3
	Max	21.4	20.1	25.3	31.1	41.9	51.5	55.9	54.4	47.4	36.0	24.5	20.6
	Min	-39.2	-31.9	-20.7	-3.0	19.9	32.9	41.3	35.0	22.4	0.3	-25.3	-37.4
West
Bethel	Mean	1.0	0.8	8.4	19.6	32.6	42.3	48.6	47.9	39.6	25.1	13.0	4.0
	Max	29.5	26.8	30.0	33.0	41.3	50.7	54.7	54.6	48.9	40.2	32.2	28.6
	Min	-28.6	-25.8	-17.5	-1.0	21.8	34.2	41.8	39.4	27.9	8.6	-11.5	-24.4

Kotzebue	Mean	-7.5	-9.2	-6.3	6.7	26.5	38.5	47.9	46.1	35.3	17.9	3.1	-5.9
	Max	21.1	18.4	20.4	27.6	35.8	49.8	56.1	54.2	46.6	33.2	24.3	20.7
	Min	-32.8	-34.5	-27.8	-13.4	11.4	30.0	38.7	34.7	22.0	0.0	-19.1	-31.7

Nome	Mean	-0.7	-1.8	1.8	12.9	28.7	38.7	45.6	45.0	35.7	21.7	10.8	1.5
	Max	27.0	24.5	26.0	29.5	37.9	47.6	53.0	52.7	46.8	37.5	29.6	25.5
	Min	-27.3	-26.8	-21.4	-7.9	15.1	29.8	36.6	33.6	21.9	4.5	-11.0	-23.9
Southwest
Adak	Mean	26.0	25.7	27.6	29.0	33.0	38.2	43.2	45.5	41.6	35.5	30.6	27.9
	Max	35.3	34.9	35.9	36.8	39.2	43.7	51.0	52.9	48.9	44.4	39.6	37.3
	Min	16.2	15.9	17.4	21.1	25.4	33.6	37.8	40.1	33.6	27.1	21.9	18.7

Cold Bay	Mean	24.7	23.8	25.6	28.7	34.4	41.2	46.5	48.1	43.3	35.3	30.4	27.2
	Max	36.2	35.4	35.1	36.6	40.6	46.4	51.0	53.1	50.6	45.4	40.1	37.6
	Min	8.6	8.5	10.6	17.3	25.8	35.4	41.5	42.7	34.4	25.0	19.1	13.6

St. Paul	Mean	21.7	19.4	20.7	24.5	31.8	38.5	44.2	46.1	41.6	33.3	28.5	24.9
	Max	34.8	33.0	32.3	33.8	37.6	43.2	47.7	49.3	47.8	43.4	38.5	36.2
	Min	4.9	1.4	2.8	10.1	22.7	32.8	40.0	41.5	32.3	22.8	16.7	11.4
Bristol Bay
King Salmon	Mean	10.7	9.6	16.2	24.3	33.3	41.4	48.0	48.0	40.8	27.4	19.0	12.9
	Max	32.0	31.6	31.9	34.4	40.3	49.0	53.6	54.1	50.1	42.3	35.4	32.7
	Min	-21.2	-18.0	-9.6	7.8	25.0	34.6	42.4	39.8	27.0	8.9	-6.9	-16.9
Cook Inlet
Anchorage	Mean	10.1	11.8	16.7	25.2	34.0	42.9	49.2	48.5	40.7	27.2	16.8	12.9
	Max	28.1	29.4	29.8	33.8	42.3	49.8	53.9	54.2	49.2	39.9	30.5	29.1
	Min	-10.9	-7.7	-1.0	11.0	25.8	35.1	43.4	39.1	26.9	10.5	0.2	-7.8

Homer	Mean	18.4	18.9	21.8	28.3	35.6	42.5	48.1	48.0	41.9	31.2	24.0	20.9
	Max	33.2	33.1	33.3	36.1	42.2	48.5	52.4	53.1	49.5	42.5	36.2	34.2
	Min	-3.3	-0.3	4.4	15.8	28.6	36.4	43.7	40.6	29.9	15.0	6.0	1.2

Talkeetna	Mean	4.4	7.8	13.8	22.8	34.1	44.1	50.2	48.9	39.9	25.1	11.8	7.6
	Max	27.7	29.1	30.1	33.0	43.7	51.2	55.5	55.7	49.7	39.5	29.1	28.9
	Min	-23.9	-16.1	-7.1	9.1	23.5	36.1	43.5	37.8	24.8	6.1	-10.6	-22.1
Copper River Basin
Gulkana	Mean	-9.5	-2.6	6.3	19.4	28.7	37.6	44.6	42.6	33.5	22.6	2.7	-4.8
	Max	19.7	23.8	23.7	30.0	38.4	47.2	51.2	50.5	43.8	35.6	24.0	24.8
	Min	-37.1	-26.3	-16.1	5.8	19.4	27.8	36.3	32.9	21.3	4.1	-21.0	-32.6
Southcentral
Kodiak	Mean	24.6	23.8	25.1	30.1	36.9	43.9	49.0	48.7	43.3	32.9	27.7	25.1
	Max	38.2	37.1	36.6	38.9	43.4	49.6	53.2	53.9	51.2	46.3	41.1	38.2
	Min	4.3	2.2	6.6	15.1	26.7	36.7	44.2	40.0	29.8	15.8	9.2	6.5

Valdez	Mean	15.4	16.9	20.8	28.6	37.2	44.6	49.2	48.0	41.8	30.2	20.2	17.4
	Max	31.3	32.6	33.0	36.5	43.8	49.8	52.4	52.5	48.9	41.7	33.5	32.9
	Min	-5.4	-3.3	1.8	15.3	28.1	38.5	44.5	38.4	27.9	12.3	2.2	-3.4

Yakutat	Mean	22.0	23.5	26.1	31.8	38.8	45.5	50.3	50.1	44.8	37.1	28.2	24.7
	Max	37.0	36.6	36.5	39.4	45.9	50.8	54.0	55.1	52.8	47.9	40.1	38.1
	Min	0.0	3.6	7.1	19.9	30.0	38.9	45.7	42.5	33.0	21.6	10.8	2.0
Southeast
Annette	Mean	29.3	30.2	32.1	35.6	40.9	46.6	51.1	52.2	48.4	41.9	34.4	31.4
	Max	42.2	41.6	41.6	43.6	48.3	52.0	55.8	57.3	54.9	50.8	45.0	42.6
	Min	8.5	10.8	15.5	24.5	32.9	40.5	45.9	47.3	38.7	28.3	17.0	11.6

Juneau	Mean	20.0	23.1	27.1	33.0	39.5	45.9	50.0	50.1	45.8	38.6	29.8	24.4
	Max	36.2	36.7	37.3	40.8	47.0	51.3	54.4	54.8	52.4	48.0	40.5	37.4
	Min	-3.8	1.4	6.4	20.0	31.4	39.5	45.7	44.2	36.5	24.3	12.6	2.9

Mean relative humidity (%) - morning and afternoon (1971 - 2000)

LOCATION	Hour	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Anchorage	3:00	74	73	71	72	72	75	80	83	82	78	79	77	76
	15:00	72	67	57	54	50	56	62	65	64	67	74	76	64
Annette	3:00	80	80	80	83	85	87	88	89	89	86	82	81	84
	15:00	76	73	68	66	65	67	69	71	73	78	77	79	72
Barrow	3:00	73	70	70	78	90	93	94	95	92	86	79	74	83
	15:00	73	70	71	76	84	85	83	87	88	85	80	74	80
Bethel	3:00	77	73	79	84	88	90	92	94	92	87	82	77	85
	15:00	76	72	74	72	63	62	68	72	70	76	80	76	72
Bettles	3:00	70	68	68	74	75	77	85	88	84	80	74	72	76
	15:00	67	63	59	60	49	47	54	61	63	72	72	72	62
Big Delta	3:00	69	73	71	72	69	74	79	81	80	82	74	74	75
	15:00	66	62	54	45	39	47	52	53	55	70	71	70	57
Cold Bay	3:00	85	84	85	86	89	92	93	94	90	86	84	87	88
	15:00	82	81	78	77	76	80	82	83	80	77	82	85	80
Fairbanks	3:00	69	67	66	66	65	73	79	84	79	77	73	71	72
	15:00	69	63	52	45	37	42	50	54	54	66	72	71	56
Gulkana	3:00	74	77	75	77	77	80	84	84	84	83	79	76	79
	15:00	71	66	55	46	40	43	48	49	52	67	76	74	57
Homer	3:00	81	80	79	81	84	88	91	90	89	83	80	80	84
	15:00	77	73	68	65	65	67	71	72	71	70	75	78	71
Juneau	3:00	81	83	86	87	89	90	90	92	93	91	87	84	88
	15:00	77	75	70	63	63	67	72	75	79	82	81	82	74
King Salmon	3:00	76	75	78	80	83	86	89	89	87	84	82	77	82
	15:00	74	68	65	61	56	59	64	66	65	69	77	76	67
Kodiak	3:00	79	78	77	78	82	86	88	88	86	79	77	76	81
	15:00	75	72	66	66	70	75	76	74	73	67	70	73	71
Kotzebue	3:00	72	70	71	77	85	87	86	86	83	81	76	73	79
	15:00	72	69	69	74	77	78	76	75	72	75	76	74	74
McGrath	3:00	73	72	73	73	76	81	84	87	84	82	78	74	78
	15:00	71	62	52	49	45	48	55	60	59	69	74	74	60
Nome	3:00	73	70	71	76	78	81	84	84	80	77	75	72	77
	15:00	72	67	68	72	70	70	74	75	68	68	73	72	71
St Paul Island	3:00	84	84	86	86	90	94	96	96	91	84	82	83	88
	15:00	83	84	83	82	83	84	89	90	83	78	81	82	84
Talkeetna	3:00	74	75	76	82	86	88	90	94	94	87	78	75	83
	15:00	68	64	59	53	50	55	61	64	64	69	71	73	63
Valdez	3:00	79	75	77	81	87	90	93	94	91	82	75	77	83
	15:00	75	69	66	63	64	67	71	73	74	73	71	76	70
Yakutat	3:00	83	85	86	90	93	95	96	96	95	91	87	84	90
	15:00	81	78	72	70	72	74	78	79	79	80	80	84	77