Climate of Hong Kong
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).
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The four seasons in Hong Kong
In the winter, the weather is generally cool by local standards, with temperatures hovering between 15 °C and 19 C. However, northeast winter monsoons bring frequent cold days which can cause the temperature to dip below 10 °C (which is very cold for Hong Kong), despite Hong Kong's location beneath the Tropic of Cancer and coastal location. Conversely, warm maritime airstreams also commonly raise the temperature above 20 °C. Temperatures as high as 28 °C have been recorded in February. Winter starts sunny in December and becomes cloudier towards February. The coldest month (January) is cool with temperatures ranging from about 14-18 degrees.
Spring brings warmer and more humid weather. It is cooler than autumn but more humid. There is a sharp increase in rainfall around April. Temperatures are also noticeably rising with an average temperature of 19 degrees at March and an average temperature of about 26 degrees at May, from mild to warm. March is mild with temperatures ranging from about 17-21 degrees. 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. August has the highest average rainfall of any month. Temperatures usually exceed 30 °C during the day, which, coupled with a high humidity, 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. September is hot with temperatures ranging from about 26-30 degrees. It is also much 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.
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| Winter | Spring | Summer | Autumn | |
|---|---|---|---|---|
| Average Temperature | Cool 15–19 °C (59–66 °F) |
Warm 20–26 °C (68–79 °F) |
Hot 26–31 °C (79–88 °F) | Warm 22–27 °C (72–80 °F) |
| Pressure |
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| Relative Humidity | Relative humidity is fairly low but it fluctuates as dry, cool air from Mainland China alternates with warm, moist air from East China Sea over Hong Kong | Relative humidity begins to rise. | Relative humidity is very high and could reach over 80%. | Relative humidity starts to fall. |
| Precipitation and Condensation |
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| Wind | Dry, cool, and strong north-easterlies blow from Mainland China | Warm, light southerlies occasionally alternate with cold, dry north-easterlines | Warm, moist southerlies blow from the sea | Winds become cooler, dries, and easterly |
| Summary | Weather condition generally stable, but anticyclones and cold fronts bring changeable weather at times. |
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Conditions become more stable and pleasant. |
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) |
| 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 |
| % 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 |
| 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.
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 23.1°C, exactly the same as the normal figure.
See also
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 2012-8-12.
External links
- 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
