Climate of Hong Kong
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The climate of Hong Kong is a monsoon-influenced humid subtropical climate (Köppen climate classification Cwa), just short of being a tropical monsoon climate (Köppen climate classification Am).
The four seasons in Hong Kong
Hong Kong has four seasons: a cool and dry winter, unstable and wet spring, hot and humid summer, and warm and pleasant autumn. Hong Kong is affected by both cool northeast monsoons and warm maritime airstreams. Most of the rainfall occurs from May to September, which is the rainy season.
Winter starts sunny in November and becomes cloudier towards February. In the winter, the weather is generally cool, with temperatures hovering between 15-19 °C. However, northeast winter monsoons bring frequent cold spells, which can cause the temperature to dip below 10 degrees in urban areas, despite Hong Kong's coastal location just below the Tropic of Cancer. The lowest temperature ever recorded was 0.0 °C in 1893, and subzero temperatures have been recorded in the northern New Territories and on high ground. Conversely, warm maritime airstreams also commonly raise the temperature above 20 °C. Temperatures as high as 28 °C have been recorded in February. The coldest months (December and January) are cool with temperatures ranging from about 14-18 degrees.
Spring brings warmer and more humid weather. It is cooler than autumn, but it is the most humid time of the year. There is a sharp increase in rainfall around April. Temperatures are also noticeably rising with an average temperature of 19 degrees in March to about 26 degrees in May, from mild to warm. Spring weather is very unstable; it could be very warm on one day, and cool on the next. The average minimum temperature of the whole season is 20 degrees. March starts off as cold as December, but gradually warms up to become mild at the end of the month. The average temperature range is about 17-21 degrees, but there are significant temperature variations throughout the month, ranging from below 10 degrees to above 25 degrees at times. April is warm with temperatures ranging from about 20-25 degrees. The average rainfall is about 175mm, about 90mm more than March. May is hot with temperatures ranging from about 24-28 degrees. Spring is the cloudiest time of the year, with March and April both averaging only around 100 hours of bright sunshine.
Summer weather is hot, humid and unstable. Thunderstorms and brief showers are common, as well as sunny conditions. June has the highest average rainfall of any month. Temperatures usually exceed 30 °C during the day, which, coupled with a high humidity (often up to 81% humidity in July), can result in an extreme heat index. Extreme heat indices are also caused by continuous sunshine and low breeze, usually last long around July and August, is a result in subtropical high pressure areas. This also occurs before typhoons hitting Hong Kong or nearby regions in the northeast, e.g. Taiwan or Eastern Coast of China, such outbound airstream bring even hotter weather, in addition to dirtier air. Nights are also warm with an average minimum temperature of 26 °C. Hong Kong is frequently hit by typhoons in summer.
Autumn is generally considered as the most pleasant season. Temperatures are still high (22–27 °C) while humidity and rainfall are considerably lower. Moreover, autumn is the sunniest season in Hong Kong, with October and November both averaging close to 200 hours of bright sunshine. There is a big decrease in rainfall around October while temperatures are gradually decreasing from hot to warm, from about 28 degrees at September to a pleasant 21.8 degrees at November. Late October to early December is considered the best time to visit. September is hot with temperatures ranging from about 26-30 degrees. It is also slightly drier than August with an average humidity of 78%. October is warm with temperatures ranging from about 23-28 degrees. November is mild-warm with temperatures ranging from about 19-24 degrees.
| Month | Average Temperature |
| Jan | 16.5-22.6°C (61.7-72.7°F) |
| Feb | 17.0-22.9°C (62.6-73.2°F) |
| Mar | 19.2-24.4°C (66.6-72.3°F) |
| Apr | 21.8-27.0°C (71.2-80.6°F) |
| May | 24.1-28.9°C (75.4-84.0°F) |
| June | 26.2-32.2°C (79.2-90.0°F) |
| July | 26.8-32.4°C (80.2-90.3°F) |
| Aug | 26.8-32.1°C (80.2-89.8°F) |
| Sep | 25.8-31.1°C (78.4-88.0°F) |
| Oct | 22.7-29.8°C (72.9-85.6°F) |
| Nov | 19.8-24.1°C (67.6-75.4°F) |
| Dec | 16.9-23.2°C (62.4-73.8°F) |
Statistics
| Climate data for Hong Kong (Hong Kong Observatory) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °C (°F) | 26.9 (80.4) |
28.3 (82.9) |
30.1 (86.2) |
33.4 (92.1) |
35.5 (95.9) |
35.6 (96.1) |
35.7 (96.3) |
36.1 (97) |
35.2 (95.4) |
34.3 (93.7) |
31.8 (89.2) |
28.7 (83.7) |
36.1 (97) |
| Average high °C (°F) | 18.6 (65.5) |
18.9 (66) |
21.4 (70.5) |
25.0 (77) |
28.4 (83.1) |
30.2 (86.4) |
31.4 (88.5) |
31.1 (88) |
30.1 (86.2) |
27.8 (82) |
24.1 (75.4) |
20.2 (68.4) |
25.6 (78.1) |
| Daily mean °C (°F) | 16.3 (61.3) |
16.8 (62.2) |
19.1 (66.4) |
22.6 (72.7) |
25.9 (78.6) |
27.9 (82.2) |
28.8 (83.8) |
28.6 (83.5) |
27.7 (81.9) |
25.5 (77.9) |
21.8 (71.2) |
17.9 (64.2) |
23.24 (73.83) |
| Average low °C (°F) | 14.5 (58.1) |
15.0 (59) |
17.2 (63) |
20.8 (69.4) |
24.1 (75.4) |
26.2 (79.2) |
26.8 (80.2) |
26.6 (79.9) |
25.8 (78.4) |
23.7 (74.7) |
19.8 (67.6) |
15.9 (60.6) |
21.4 (70.5) |
| Record low °C (°F) | 0.0 (32) |
2.4 (36.3) |
4.8 (40.6) |
9.9 (49.8) |
15.4 (59.7) |
19.2 (66.6) |
21.7 (71.1) |
21.6 (70.9) |
18.4 (65.1) |
13.5 (56.3) |
6.5 (43.7) |
4.3 (39.7) |
0.0 (32) |
| Average rainfall mm (inches) | 24.7 (0.972) |
54.4 (2.142) |
82.2 (3.236) |
174.7 (6.878) |
304.7 (11.996) |
456.1 (17.957) |
376.5 (14.823) |
432.2 (17.016) |
327.6 (12.898) |
100.9 (3.972) |
37.6 (1.48) |
26.8 (1.055) |
2,398.4 (94.425) |
| Avg. rainy days (≥ 0.1 mm) | 5.37 | 9.07 | 10.90 | 12.00 | 14.67 | 19.07 | 17.60 | 16.93 | 14.67 | 7.43 | 5.47 | 4.47 | 137.65 |
| Average relative humidity (%) | 74 | 80 | 82 | 83 | 83 | 82 | 81 | 81 | 78 | 73 | 71 | 69 | 78.0 |
| Mean monthly sunshine hours | 143.0 | 94.2 | 90.8 | 101.7 | 140.4 | 146.1 | 212.0 | 188.9 | 172.3 | 193.9 | 180.1 | 172.2 | 1,835.6 |
| Percent possible sunshine | 42 | 29 | 24 | 27 | 34 | 36 | 51 | 47 | 47 | 54 | 54 | 51 | 42 |
| Source: Hong Kong Observatory (normals 1981–2010, extremes 1884–1939 and 1947–present)[1][2] | |||||||||||||
Climate of the past years
1997. The year 1997 was the wettest year since records began in 1884. Rainfall at the Hong Kong Observatory amounted to 3,343.0 millimetres (131.61 in), 51 per cent above normal and exceeding the previous record set in 1982.
1998. It was the warmest year since records began in 1884. The annual mean temperature was 24.0 °C (75.2 °F), 0.2 °C (0.4 °F) higher than the previous record set in 1966. The annual mean daily minimum temperature of 22.1 °C (71.8 °F) was also the highest on record.
1999. With an annual mean temperature of 23.8 °C (74.8 °F), 1999 was the third warmest year on record. The monthly mean temperatures for all months except May, August and December were above their respective normal figures.
2000. The year 2000 was warmer and wetter than usual. The mean temperature of 23.3 °C (73.9 °F) was the tenth highest on record and the mean minimum temperature of 21.5 °C (70.7 °F) was the sixth highest. The annual total rainfall of 2,752.3 millimetres (108.36 in) was 24 per cent above normal.
2001. The year 2001 was warmer and wetter than usual. The mean temperature of 23.6 °C (74.5 °F) was 0.6 °C (1.1 °F) above normal, ranking the sixth highest on record. The mean minimum temperature of 21.8 °C (71.2 °F) was the second highest on record. The annual total rainfall of 3,091.8 millimetres (121.72 in) also ranked the fourth highest.
2002. The year 2002 was the second warmest year on record. The mean temperature of 23.9 °C (75.0 °F) was 0.9 °C (1.6 °F) above normal.
2003. The year 2003 was the sixth warmest year since records began in 1884. The mean temperature, 23.6 °C (74.5 °F), was 0.6 °C (1.1 °F) above normal.
2004. Globally, the year 2004 was the fourth warmest year since instrumental temperature record began in 1861. In Hong Kong, 2004 was the ninth warmest year on record. The annual mean temperature was 23.4 °C (74.1 °F), 0.4 °C (0.7 °F) above normal.
2005. Locally in Hong Kong, 2005 was the third wettest year on record. The total rainfall of 3,214.5 millimetres (126.56 in) was 45.2 percent above normal.
2006. Globally, the year 2006 is the sixth warmest year on record. In Hong Kong, it was the eighth warmest year since record began in 1884. The annual mean temperature of 23.5 °C (74.3 °F) was 0.5 °C (0.9 °F) higher than normal.
2008. On the morning of 7 June Hong Kong was lashed by a torrential storm, which dumped up to 300 mm (11.8 in) of rain including 145.5 mm (5.73 in) between 8 am and 9 am killing 3 people. The storm also caused traffic delays and dozens of flight delays.
2009. The year 2009 was warmer than usual with an annual temperature of 23.5 degrees. The average temperature in February reached a record high of 20.5 degrees, 4.2 degrees above the climatological normal. Also, prolonged hot weather extended from summer into late September, with altogether 30 days having daily maximum temperatures of 33 degrees or above, the highest since 1963. The Very Hot Weather Warning was in effect for a total of 40 days, the highest number since the warning started operation in 2000. The year 2009 was also drier than usual. The annual rainfall of 2182.3 millimetres was about 8 percent below normal.
2010. Year 2010 started off with three notably warm months with monthly mean temperatures 0.7 to 1.6 degree above normal. This anomaly was mostly offset by the well below normal monthly mean temperatures in April and June, the former due to frequent passage of late season cold fronts and the latter due to gloomy weather. With insignificant anomalies of monthly mean temperatures in the second half of the year, the annual mean temperature in 2010 ended up to 23.2 degrees, close to the normal figure of 23.1 degrees. During the year, there were 13 very hot days (daily maximum temperature at 33.0 degrees or above) and 21 cold days (daily minimum temperature at 12.0 degrees or below), 3 days and 2 days more than normal respectively.
2011. The first month of 2011 was the coldest January since 1977. The temperature did not go above 20 degrees, and the daily mean temperature of the month was only 13.7 degrees. The mean temperature of 2011 was 23.0 degrees. 0.1 degrees below the normal figure of 23.1 degrees. The year 2011 was also an exceptionally dry year. With well below normal rainfall in the first nine months, the annual rainfall of 1476.7 millimetres was about 38 per cent below normal, the lowest since 1963.
2012. In Hong Kong, 2012 started with significantly colder than normal weather in January and February which is mainly due to the stronger northeast monsoon over southern China usually in the presence of La Nina. However, with La Nina fading out in spring, the below-normal temperature was compensated by the exceptionally warm weather in April, May and August in 2012. Overall, the average temperature of 2012 was 23.4 degrees, 0.1 degrees above the 1981-2010 normal figure of 23.3 degrees
See also
- Geography of Hong Kong
- Environment of Hong Kong
- Great Hong Kong Typhoon of 1937
- 1906 Hong Kong typhoon
References
- ↑ "Monthly Meteorological Normals for Hong Kong". Hong Kong Observatory. Retrieved 2012-01-03.
- ↑ "Extreme Values and Dates of Occurrence of Extremes of Meteorological Elements between 1884-1939 and 1947-2011 for Hong Kong". Hong Kong Observatory. Retrieved 2012-08-12.
External links
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Wikimedia Commons has media related to Climate of Hong Kong. |
- Hong Kong Observatory web site
- Hong Kong Underground Observatory web site
- The Climate Information site from HKO
- Explanation of Hong Kong's Typhoon Signal System
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