Climate Chofu Airport 2020-2024

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

Calculated from historical METAR data of Yokota Air Base (RJTY) between 2020 and 2024.

VFR conditions (%)

Month	Average	2024	2023	2022	2021	2020
January	90.7	95	87	90	91	83
February	89.1	77	90	92	97	90
March	81.5	83	76	75	91	77
April	84.2		86	71	90	88
May	83.2		82	78	79	80
June	73.3		67	71	88	74
July	78.0		96	79	75	63
August	83.5		86	71	81	97
September	74.6		78	69	67	73
October	79.2		89	77	78	86
November	88.8		85	90	91	93
December	90.5		92	80	98	90
Average	82.8	84.7	83.9	77.5	84.8	82.1

50th best VFR conditions of Japan

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	97.2	100	97	96	99	94
February	94.4	86	93	96	98	96
March	91.4	89	92	86	96	90
April	92.9		94	90	97	91
May	94.8		97	91	90	96
June	90.2		86	90	97	91
July	93.6		99	94	91	91
August	95.3		99	93	93	99
September	92.5		90	90	89	94
October	91.7		94	87	96	96
November	96.6		98	96	94	99
December	98.6		100	100	100	100
Average	93.6	91.3	94.7	91.8	94.9	94.4

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	9.6	12	9	9	9	11
February	11.0	12	12	9	13	12
March	15.3	14	17	16	17	15
April	19.3		21	19	19	18
May	23.3		23	23	23	23
June	25.9		26	27	26	26
July	29.4		33	31	29	26
August	31.5		33	31	32	33
September	27.1		30	27	26	27
October	21.1		23	20	22	20
November	17.2		19	18	17	18
December	11.8		14	12	12	12
Average	19.3	12.7	21.6	20.4	20.6	20.0

32nd highest temperature of Japan

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	-1.1	0	-1	-2	-2	2
February	0.5	3	1	-2	1	2
March	5.3	3	7	5	7	5
April	9.2		10	10	9	7
May	14.0		14	13	15	15
June	18.7		19	19	19	19
July	22.6		24	24	22	21
August	23.7		24	24	23	24
September	20.0		23	21	19	20
October	13.1		13	11	13	13
November	7.6		8	8	7	8
December	1.4		3	2	-1	1
Average	10.3	2.0	12.1	11.3	11.1	11.3

23rd lowest temperature of Japan

Average lowest temperature per day

The minimum temperature is typically observed just before sunrise.

Precipitation (%)

Month	Average	2024	2023	2022	2021	2020
January	5.3	5	6	7	3	11
February	8.0	16	13	8	3	1
March	13.7	16	21	15	9	12
April	12.8		14	26	5	16
May	12.9		18	17	13	14
June	16.1		26	20	6	12
July	13.3		6	15	20	23
August	8.7		7	13	14	2
September	11.8		13	16	17	10
October	16.9		12	18	12	17
November	5.0		5	9	4	1
December	2.6		1	5	4	1
Average	11.0	12.6	12.3	14.9	9.5	10.4

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	6.5	7	5	8	5	6
February	7.6	8	9	7	8	8
March	7.6	10	6	7	8	8
April	8.5		8	7	8	10
May	8.0		9	7	8	8
June	6.7		6	7	7	7
July	6.6		7	7	6	6
August	7.0		8	7	7	6
September	6.4		7	6	5	7
October	6.0		6	5	7	6
November	5.5		6	6	5	6
December	5.2		5	5	6	5
Average	6.9	8.3	6.8	6.6	6.7	6.8

32nd highest wind speed of Japan

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	021°	046°	025°	036°	031°
February	025°	031°	039°	055°	037°
March	023°	100°	115°	083°	053°
April		151°	110°	104°	130°
May		144°	136°	169°	164°
June		163°	156°	160°	169°
July		167°	160°	155°	172°
August		169°	158°	164°	162°
September		146°	060°	056°	106°
October		038°	041°	047°	042°
November		037°	040°	043°	056°
December		084°	039°	038°	063°

Prevailing wind direction

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