NOTE: Data from Western Regional Climate Center (WRCC).

MEAN MONTHLY AND ANNUAL NUMBER OF CLEAR DAYS

This data is based on daylight hours only. A clear day denotes zero to 3/10 average sky cover. Partly cloudy is 4/10 to 7/10 tenths. Cloudy is 8/10 to 10/10 tenths. There is no table for partly cloudy. Simply add number of clear days with cloudy days and subtract from total days in the month to get number of partly cloudy days. Annual totals may differ from the 12 month totals due to rounding. (m) - In Barrow, the sun sets below the horizon on November 18 and does not rise again until January 24. Data is incomplete between these dates.

* = less than 1/2 day
 
 
 

City	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Hilo	6	5	3	1	1	2	1	2	3	3	3	5	36
Honolulu	9	8	8	6	7	6	7	8	8	7	7	8	90
Kahului	13	11	11	8	10	11	11	12	12	11	11	12	131
Lihue	8	7	5	3	3	3	3	4	5	5	4	6	56

MEAN MONTHLY AND ANNUAL NUMBER OF CLOUDY DAYS

This data is based on daylight hours only. A clear day denotes zero to 3/10 average sky cover. Partly cloudy is 4/10 to 7/10 tenths. Cloudy is 8/10 to 10/10 tenths.There is no table for partly cloudy. Simply add number of clear days with cloudy days and subtract from total days in the month to get number of partly cloudy days. Annual totals may differ from the 12 month totals due to rounding. (m) - In Barrow, the sun sets below the horizon on November 18 and does not rise again until January 24. Data is incomplete between these dates.
 
 
 

City	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Hilo	13	13	18	20	19	17	18	17	15	16	17	15	197
Honolulu	9	8	9	10	9	6	5	6	6	8	9	9	94
Kahului	8	7	9	10	8	6	5	5	6	8	8	8	90
Lihue	10	9	12	13	11	9	10	9	7	10	12	11	125

DAY OF STORM

* = less than 1/2 day

MEAN MONTHLY AND ANNUAL NUMBER OF THUNDERSTORMS
 
 
 

City	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Hilo	1	1	2	1	1	*	*	*	1	1	1	1	10
Honolulu	1	1	1	1	*	*	*	*	1	1	1	1	7
Kahului	1	1	*	1	*	0	*	*	*	*	*	1	4
Lihue	1	1	1	*	1	*	*	*	*	1	1	1	8

MEAN MONTHLY AND ANNUAL DEW POINT TEMPERATURE (F)

Dew point (dew-point temperature)----The temperature to which air must be cooled (at constant pressure and constant water vapor content) for saturation to occur.When the dew point falls below freezing it is called the frost point.
 
 
 

City	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Hilo	63	63	64	65	66	68	69	70	69	69	68	65	66
Honolulu	63	62	62	63	64	66	67	68	69	68	67	64	65
Kahului	58	58	59	59	60	61	63	64	63	63	62	59	61
Lihue	62	62	63	65	66	68	70	70	70	70	67	65	67

MEAN MONTHLY AND ANNUAL WET BULB TEMPERATURES (F)

The lowest temperature that can be obtained by evaporating water into the air.
 

City	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Hilo	66	66	67	68	69	70	71	72	72	71	70	67	69
Honolulu	66	66	67	68	69	70	72	72	73	72	70	68	69
Kahului	67	67	67	68	69	71	67	67	67	67	66	63	67
Lihue	66	66	67	68	69	72	73	73	73	72	70	68	70

MEAN MONTHLY AND ANNUAL PERCENT OF POSSIBLE SUNSHINE

 
 
 

City	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Hilo	46	46	42	37	37	44	41	42	43	39	33	37	41
Honolulu	65	68	72	70	72	74	76	77	77	70	65	63	67
Kahului	64	64	64	63	68	72	71	71	73	68	62	63	67
Lihue	54	56	55	54	60	63	62	65	66	58	49	49	58

MEAN MONTHLY AND ANNUAL PERCENT RELATIVE HUMIDITY (MORNING)

Average morning relative humidity values based on early morning readings when highest values generally occur. The observation times (Local Standard Time) of morning humidities are shown after the city (column "LST").
 
 
 

City	LST	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Hilo	02	83	83	85	88	87	86	88	87	87	87	86	85	86
Honolulu	02	81	79	76	75	74	73	73	72	74	76	78	80	76
Kahului	02	84	81	80	81	81	80	80	78	79	80	81	82	81
Lihue	02	82	81	81	81	81	79	79	80	80	82	81	81	81

MEAN MONTHLY AND ANNUAL PERCENT RELATIVE HUMIDITY (AFTERNOON)

Average afternoon relative humidity values based on late afternoon readings when lowest valuesgenerally occur. The observation times (Local Standard Time) of afternoon humidities are shown after the city (column "LST").
 
 
 

City	LST	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Annual
Hilo	14	66	65	67	70	67	65	68	68	69	70	70	68	68
Honolulu	14	62	59	57	56	54	52	52	51	52	56	59	61	56
Kahului	14	64	62	60	59	56	55	56	55	55	58	60	62	58
Lihue	14	67	66	67	67	67	65	66	66	65	68	69	68	67

MEAN MONTHLY AND ANNUAL NUMBER OF HOURS WITH MEASURABLE PRECIPITATION

(*) = Less than 1/2 hour

Maximum 1-hour totals are based on data from top of the hour. Maximum 60-minute totals will be greater.
 
 

WITH PERCENT OF HOURS AND MAXIMUM 1-HOUR TOTALS
 

City	Years	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Year	Percent Hours	Max 1-HR (IN)
Hilo	1962-1999	110	103	159	168	139	132	159	143	122	124	155	134	1648	18.8	4.17
Honolulu	1963-1999	37	27	31	25	17	11	16	11	21	36	34	41	307	3.5	2.28
Kahului	1963-1999	56	42	49	37	17	10	17	15	11	20	41	49	364	4.2	2.96
Lihue	1963-1999	61	48	59	59	47	42	53	42	38	57	71	69	646	7.4	3.55