Climate Christiansted Harbor Seaplane Base 2020-2024

Climate and trends: average temperature, flight conditions, precipitation, wind speed and direction.

Calculated from historical METAR data of Henry E Rohlsen Airport (TISX) between 2020 and 2024.

VFR conditions (%)

Month	Average	2024	2023	2022	2021	2020
January	97.0	93	96	98	96	97
February	96.2	87	95	96	98	98
March	96.7	92	95	98	97	96
April	96.1		92	97	97	97
May	95.5		96	93	97	92
June	91.1		79	94	95	88
July	92.1		78	90	94	95
August	95.3		93	94	94	94
September	94.1		94	87	98	95
October	90.8		88	92	92	98
November	94.1		91	89	100	95
December	96.5		89	98	100	97
Average	94.3	90.5	89.9	93.7	96.3	95.0

VFR conditions during daylight period

Percentage of observations where the VFR minimums for ceiling and visibility are met: visibility of 8 km or more and a ceiling of 3,000 ft or more. Only observations between sunrise and sunset are taken into account.

Marginal VFR conditions (%)

Month	Average	2024	2023	2022	2021	2020
January	99.4	99	99	100	100	99
February	98.8	98	99	98	99	99
March	99.5	100	100	99	100	100
April	98.4		98	100	99	99
May	99.4		100	100	99	99
June	99.0		99	100	99	97
July	99.2		98	98	100	100
August	98.9		98	98	99	99
September	98.6		100	95	100	100
October	94.9		98	99	96	99
November	98.1		96	96	100	98
December	99.3		99	100	100	99
Average	98.7	98.9	98.5	98.6	99.2	99.0

Marginal VFR conditions or better during daylight period

Percentage of observations where the MVFR minimums for ceiling and visibility are met: visibility of 5 km or more and a ceiling of 1,000 ft or more. Only observations between sunrise and sunset are taken into account.

Maximum temperatures (°C)

Month	Average	2024	2023	2022	2021	2020
January	29.0	31	29	29	29	29
February	29.0	30	29	29	29	30
March	29.2	31	29	29	29	29
April	29.7		29	30	30	30
May	30.6		31	31	31	31
June	31.5		32	32	31	33
July	31.7		32	32	32	32
August	32.0		33	32	31	33
September	32.0		35	32	32	32
October	30.4		32	31	31	32
November	30.8		32	31	31	30
December	29.8		30	29	30	29
Average	30.4	30.3	31.0	30.5	30.5	30.8

25th highest temperature of United States

Average highest temperature per day

The maximum temperature is typically observed some hours after noon.

Minimum temperatures (°C)

Month	Average	2024	2023	2022	2021	2020
January	22.4	24	23	22	23	22
February	22.0	22	22	21	24	22
March	22.2	21	22	22	23	23
April	23.2		23	24	23	24
May	23.8		25	25	25	21
June	25.4		27	26	25	27
July	25.5		26	26	24	27
August	25.8		28	27	25	27
September	24.7		27	26	25	26
October	23.0		25	26	22	22
November	23.8		25	24	24	24
December	22.9		22	22	24	22
Average	23.5	22.3	24.4	24.1	23.7	23.7

Average lowest temperature per day

The minimum temperature is typically observed just before sunrise.

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	3.5	5	4	3	5	4
February	3.6	5	5	4	2	5
March	2.5	4	2	3	1	5
April	3.1		4	4	2	3
May	3.1		2	2	3	3
June	2.9		3	0	4	4
July	3.8		7	2	2	4
August	5.4		6	4	5	7
September	7.4		4	17	2	6
October	5.4		7	5	5	6
November	6.5		6	10	3	5
December	3.8		5	2	1	6
Average	4.2	4.9	4.6	4.7	2.8	4.7

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 (knots)

Month	Average	2024	2023	2022	2021	2020
January	10.7	11	11	11	11	10
February	11.6	9	13	11	15	12
March	11.3	10	11	13	12	11
April	11.7		11	14	11	10
May	11.8		10	13	12	11
June	12.4		12	13	13	12
July	13.4		13	17	14	13
August	11.7		11	11	12	12
September	9.6		10	11	9	9
October	8.7		8	10	10	10
November	9.9		10	10	10	11
December	10.5		10	8	12	10
Average	11.1	10.1	10.9	11.9	11.8	10.9

25th highest wind speed of United States

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	091°	080°	087°	077°	075°
February	089°	074°	072°	088°	087°
March	093°	087°	087°	081°	076°
April		103°	090°	092°	103°
May		117°	099°	096°	108°
June		111°	096°	090°	096°
July		094°	087°	090°	087°
August		100°	090°	087°	088°
September		102°	096°	096°	085°
October		110°	095°	103°	095°
November		100°	089°	081°	092°
December		076°	045°	073°	072°

Prevailing wind direction

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