Kwajalein Climate Summary

83.1 °F / 28.4 °C
E at 12 MPH
83%
77.7°F / 25.4 °C
29.83" (1010 mb)
10 mile(s)
clear
2020.08.04 1020 UTC

Kwajalein Climate Summary

Rain Drop

Kwajalein’s location gives it a tropical marine climate characterized by two main seasons, a wet season and a dry season, with little temperature variation between them. The atoll experiences the dry season typically from mid-December to mid-May dominated by brisk east-northeasterly Trade Winds, and the wet season from mid-May to mid-December where winds tend to be lighter and of more variable direction. Normal annual rainfall is approximately 100 inches; approximately 72% of which occurs during the wet season. A pronounced diurnal cycle is present, with two thirds of atoll rainfall typically recorded between midnight and sunrise.  On average, the prevailing wind direction is from the east-northeast during the entire year, although, winds may become more variable, especially during the wet season, when occasional southerly or even westerly winds occur. Average wind speed is near 17 mph in the dry season and near 12 mph during the wet season. Although thunderstorms do occur, most of the precipitation at Kwajalein comes from rain showers.

The average daily maximum temperature is 86.5°F (30.3oC); the average minimum is 77.6°F (25.3oC). Average relative humidity ranges from 78% at local noon to 83% at midnight.

Weather Summary Table

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Daylight (Hours)

11.6

11.8

12.0

12.2

12.4

12.5

12.4

12.2

12.0

11.8

11.6

11.5

Avg. High Temp (°F)

85

86

86

87

87

87

87

87

87

86

86

86

Avg. Low Temp (°F)

78

78

78

79

79

78

78

78

78

78

78

78

Normal Wind Direction (from)

NE - E

NE - E

NE - E

NE - E

NE - E

NE - E

NE - E*

NE - E*

NE - E*

NE - E*

NE - E*

NE - E*

Avg. Wind Speed (mph)

17 - 22

16 - 21

15 - 20

14 - 19

13 - 18

12 - 17

11 - 16

9 - 14

11 - 16

13 - 18

14 - 19

16 - 21

Daily Chance of Rainfall % ***

55%

45%

50%

55%

60%

65%

70%

80%

80%

85%

75%

60%

Avg. Rainfall **
(inches)

4.0

3.3

3.6

6.2

6.6

7.9

9.9

10.4

10.9

11.8

11.1

8.1

Heavy Rain Days
# Days >= 1”

1

1

1

2

3

3

3

3

3

4

3

2

Average Cloud Cover % ****

85%

80%

80%

80%

80%

85%

85%

85%

90%

90%

85%

85%

High Wind Days *
# Days >= 35mph

4

4

4

2

2

3

4

2

2

3

6

6

West Winds *

--------------------Higher Risk Period--------------------

Rough Seas *

(small boat hazards and shoreline flooding)

----Moderate Risk----

-----------------------Low Risk-----------------------

------Higher Risk------


* Significant west-wind and west-swell events are more likely to occur in strong El Nino years.
** Averages can be misleading. The tropical climate normally produces long wet or dry periods. On small tropical islands, without mountain effects, about 2/3 of annual rainfall occurs between midnight and sunrise.
*** Shows probability of experiencing at least a few drops of rain (trace or more) anytime in the 24-hour day.
**** Many high clouds are generated from deep tropical convection patterns. These high clouds frequently spread into our area. Average cloud cover statistics include contributions from thin/translucent high clouds that are not always visible from the ground.

For more climatological surface data, see this page.

Kwajalein is on the eastern edge of the Western Pacific typhoon generation zone, an area where tropical depressions frequently form.  During the modern era of record keeping, since 1919, a fully developed typhoon has never made a direct strike on Kwajalein Atoll. However, tropical storms have had significant impacts upon Kwajalein's atoll with sustained winds ranging from 25-52 mph. The table below details several notable tropical storms that have approached the atoll.


  Storm Name      Year    Month   Day Closest Point of
Approach at Kwaj

[nmi]
Max Sustained
Wind at Kwaj

[kt]
Max Wind
Gust at Kwaj

[kt]
Lowest Pressure
at Kwaj

[mb]
 Kit ? ? ? ?
 Lola ? ? ? ?
 Mamie ? ? ? ?
 Ophellia 1958  ? ? ? ?
 Phyliss 1969  ? ? ? ?
 Mary 1977  ? ? ? ?
 Rita 1978  ? ? ? ?
 Alice 1979  40 42 56 ?
 Freda 1981  12  ? 31 43 ?
 Pamela 1982  11  26  18 43 58 ?
 Norris 1986  12  22  ? 31 42 ?
 Roy 1988  35 43 57 991.5
 Owen 1990  11  21  ? 22 35 ?
 Zelda 1991  11  29  19 52 71 990.1
 Axel 1992  ? 30 46 ?
 Gay 1992  11  18  110 25 30 1001.0
 Paka 1997  12  11  83 39 47 1003.1
 Talas 2004  12    10/11  16 40 56 1002.9
 Bavi 2015  11/12  97 36 44 997.2

 

Tropical Cyclone Categories Based on Sustained Surface Winds
Tropical Depression: <= 38mph (33kts)
Tropical Storm: 39-73mph (34-63kts)
Typhoon: 74-110mph (64-95kts)
Super Typhoon: >= 150mph (130kts)