Four Seasons at … (… 的一年四季) : 您除左去飛…都可以了解下人地既地方嫁麻~

June 8, 2024

Hong Kong

Definition of seasons ｜Hong Kong Observatory(HKO)｜Educational Resources

Background
香港位於亞熱帶，一年中亦有不同的氣候特徵，例如一、二月較冷，七、八月則較熱，六至八月較為多雨，而十一、十二月則較乾燥及雲量較少。目前，香港天文台採用「氣象季節」來劃分四季，並提供各季節的氣候資料分析和氣候服務，其範圍包括季節預測、趨勢分析、排名計算、氣候變化研究等。「氣象季節」是將一年分為四個長度大致相等的時段（即每三個月為一段），以北半球為例，最溫暖和最冷的時段分別指定為夏季（六月、七月和八月）和冬季（十二月、一月和二月），介乎於夏季和冬季之間就是秋季（九月、十月和十一月）和春季（三月、四月和五月）。這個定義亦與香港30年（1981-2010）月平均氣溫（圖1）所描繪的年度溫度週期大致吻合，即六月、七月和八月通常是最熱的三個月，而十二月、一月和二月是一年中最冷的三個月。
使用「氣象季節」的優點是每年的季節長度和季節開始時間大致不變，在研究分析、結果比較和服務產品發展上較為簡單方便。而公眾和特別用戶亦可以容易理解和使用相關數據和產品。世界上主要的氣候中心，如北京氣候中心、歐洲中期天氣預報中心、日本氣象廳、美國國家海洋和大氣管理局等也基於「氣象季節」來進行氣候分析和提供一些氣候服務。
除了「氣象季節」外，一些研究人員和氣象機構亦會以不同氣象要素和指標來劃分四季及其他特定季節，例如以滑動平均氣溫來計算每年進入四個季節的日期、以降雨量來計算雨季的開始日期、以季候風水文循環的特徵來判斷進入季風季節的日期等。這些以觀測數據為基礎的季節劃分法一般較複雜，較多用於氣候研究之上。而計算出來的季節開始和結束日期每年都有明顯變化，同一套劃分法在不同地區亦不一定完全適用。
Hong Kong’s climate is sub-tropical with different climatic characteristics throughout the year. For example, January and February are colder, July and August are hotter, June to August are rainier, while November and December are drier and less cloudy. Currently, the Hong Kong Observatory adopts “meteorological seasons” approach to divide the four seasons and provide climate data analysis and climate services in Hong Kong (e.g. seasonal predictions, trend analysis, ranking calculations, climate change studies, etc.). The definition of “meteorological seasons” refers to the partition of a year into four periods of roughly equal length (i.e. three months as a period). For the Northern Hemisphere, the warmest and coldest periods are respectively designated as Summer (June, July and August) and Winter (December, January and February), and the in-between periods as Autumn (September, October and November) and Spring (March, April and May). This definition is generally in line with the annual temperature cycle depicted by the 30-year (1981 – 2010) monthly mean temperatures in Hong Kong (Figure 1), i.e. June, July and August are usually the three hottest months, while December, January and February are the three coldest months in a year.
The merit of using “meteorological seasons” is that the length of the seasons and the start time of the seasons are generally unchanged. It will be simpler and more convenient for research analysis, results comparison and development of service products. It is also easier for the public and special users to understand and use relevant data and products. Major climate centres in the world, such as Beijing Climate Center, European Centre for Medium-Range Weather Forecasts, Japan Meteorological Agency, National Oceanic and Atmospheric Administration, also adopt “meteorological seasons” in climate monitoring and some of their climate services.
In addition to “meteorological seasons”, some researchers and meteorological agencies also use different meteorological elements and indices to determine the “four seasons” and other specially defined seasons. For example, using running average of daily temperatures to determine the commencement date of the four seasons in a year, using rainfall amount to identify the beginning of the rainy season, and utilising the key features of the monsoon hydrologic cycle to assess the onset time of the monsoon seasons. This observational-based approach in defining seasons is generally more complicated and more commonly used for research purposes. Moreover, the start and end dates of a season as calculated by such approach usually vary significantly from year to year, and the same approach may not be directly applicable to different regions.

根據世界氣象組織的初步評估，2023年可能是全球有記錄以來最暖的一年。全球平均海平面在2023年繼續上升，創下歷史新高。年內北極海冰覆蓋範圍持續低於平均水平，而9月份的全年最低值是有衛星記錄以來的第六低。2023年各類極端天氣事件在全球多處肆虐，當中包括影響歐洲、北非、華南、日本及東南亞大部分地區等世界多處的熱浪；非州西北部、大非洲之角地區、伊比利亞半島部分地區、中亞及亞洲西南部的部分地區、中美洲多處、南美州北部、加拿大及美國部分地區的嚴重乾旱；極端降雨引致的嚴重水浸亦影響中國、印度、巴基斯坦、尼泊爾、希臘、保加利亞南部、土耳其部分地區、利比亞東北部、西班牙及新西蘭北島；以及熱帶氣旋在莫桑比克、馬拉維、馬達加斯加、津巴布韋、斯里蘭卡、緬甸、印度、孟加拉、菲律賓及中國帶來的嚴重破壞及重大傷亡。而山火亦在希臘、夏威夷和加拿大肆虐，造成嚴重破壞。

2022年的拉尼娜事件持續至2023年1月。赤道太平洋中部及東部水溫在隨後的月份持續上升。一次厄爾尼諾事件在2023年8月形成，並持續至年底。

本港方面，由於全年十二個月都較正常溫暖，2023年是有記錄以來其中一個第二暖的一年，全年平均氣溫達24.5度，較1991-2020年正常值[1]高1.0度。而全年平均最低氣溫22.6度及平均最高氣溫27.2度分別為自1884年有記錄以來其中一個最高及其中一個第二高。而夏季(6月至8月)的平均氣溫達29.7 度，是有記錄以來最高。香港天文台於7月27日錄得全年最高氣溫36.1度，是有記錄以來其中一個第三高。2023年的酷熱天氣[2]日數、熱夜[3]數目及極端酷熱天氣[4]日數分別為54天、56天及4天，是有記錄以來其中一個最多、第二多及其中一個第五多。

天文台於12月23日錄得全年最低氣溫8.1度。全年寒冷天氣[5]日數為14天，較1991-2020年正常值少1.2天。

2023年春季及夏季的雨量較少，而秋季則非常多雨。主要歸因於秋季的破紀錄雨量，2023年本港的全年雨量為2,774.5毫米，較1991-2020年正常值2,431.2毫米高約百分之14。年內天文台曾發出八次紅色暴雨警告及兩次黑色暴雨警告。2023年的雷暴日數為40天，較1991-2020年正常值少約2天。

2023年共有19個熱帶氣旋影響北太平洋西部及南海，較長期(1961-2020年)平均的約30個為少。全年有11個熱帶氣旋達到颱風或以上強度[6]，低於長期平均的約15個，當中有5個熱帶氣旋達到超強颱風強度 (中心附近最高十分鐘持續風速達到每小時185公里或以上)。本港方面，年內有5個熱帶氣旋令天文台需要發出熱帶氣旋警告信號，稍少於長期年平均的約6個。天文台在9月蘇拉、10月小犬及7月泰利吹襲本港期間分別發出十號颶風信號、九號烈風或暴風風力增強信號及八號烈風或暴風信號。

Temerature

Globally, 2023 is likely to be the warmest year on record according to the World Meteorological Organization’s preliminary assessment. Global mean sea level continued to rise, reaching a new record high in 2023. Over the Arctic, sea-ice extent remained well below average in the year and the minimum sea-ice extent in September was the sixth lowest in the satellite record. In 2023, different parts of the world were ravaged by various extreme weather events, including heatwaves in many parts of the world, including Europe, North Africa, southern China, Japan and much of Southeast Asia; severe drought in northwestern Africa, the Greater Horn of Africa region, parts of the Iberian Peninsula, parts of central and southwest Asia, many parts of Central America, northern South America, parts of Canada and the United States; extreme rainfall triggered severe flooding in China, India, Pakistan, Nepal, Greece, southern Bulgaria, parts of Türkiye, northeastern Libya, Spain, and the North Island of New Zealand; and severe damages and heavy casualties brought by tropical cyclones in Mozambique, Malawi, Madagascar, Zimbabwe, Sri Lanka, Myanmar, India, Bangladesh, the Philippines and China. Rampant wildfires also wreaked great havoc in Greece, Hawaii and Canada.

The La Niña event of 2022 lasted till January 2023. Sea surface temperatures of the central and eastern equatorial Pacific continued to increase in the following months. An El Niño event was established in August 2023 and persisted through to the end of the year.

In Hong Kong, with all twelve months warmer than usual, 2023 was one of the second warmest years on record with the annual mean temperature reaching 24.5 degrees, 1.0 degree above the 1991-2020 normal[1]. The annual mean minimum temperature of 22.6 degrees and annual mean maximum temperature of 27.2 degrees were respectively one of the highest and one of the second highest since records began in 1884. In particular, the mean temperature for summer (June to August) reached 29.7 degrees, the highest on record. The highest temperature recorded at the Hong Kong Observatory in the year was 36.1 degrees on 27 July, one of the third highest on record. There were 54 Very Hot Days[2], 56 Hot Nights[3] and 4 Extremely Hot Days[4] in Hong Kong in 2023, respectively ranking one of the highest, the second highest and one of the fifth highest on record.

The lowest temperature recorded at the Observatory in the year was 8.1 degrees on 23 December. The number of Cold Days[5] in the year was 14 days, 1.2 days less than the 1991-2020 normal.

Rainfall

2023 was characterised by a dry spring and summer, and very wet autumn. Mainly attributing to the record-breaking rainfall in autumn, the annual total rainfall in 2023 was 2774.5 millimetres, about 14 percent above the 1991-2020 normal of 2431.2 millimetres. Eight red rainstorm warnings and two black rainstorm warnings were issued by the Observatory in the year. The number of days with thunderstorms reported in Hong Kong was 40 days in 2023, about 2 days less than the 1991-2020 normal.
Tropical cyclones
A total of 19 tropical cyclones occurred over the western North Pacific and the South China Sea in 2023, less than the long-term (1961-2020) average of about 30. There were 11 tropical cyclones reaching typhoon intensity[6] or above during the year, less than the long-term average of about 15, and five of them reached super typhoon intensity (with maximum 10-minute wind speed of 185 km/h or above near the centre). In Hong Kong, five tropical cyclones necessitated the issuance of tropical cyclone warning signals, slightly less than the long-term average of about six in a year. The Hurricane Signal No. 10 was issued during the passage of Saola in September, the Increasing Gale or Storm Signal No. 9 was issued during the passage of Koinu in October and the Gale or Storm Signal No. 8 was issued during the passage of Talim in July.

Phoenix

Key notes from this clip:

  • palo verde tree – the flower may cause somebody allergy (sign: swollen eyes, runny nose, clogged sinuses)
  • fansinating history: state of Arizona (AZ) officially became a state was 14 Feb 1912
  • be aware of a few of critters (= creature)/ wildelife that can be intrusive to your backyard: snake (rattlesnake), lizard (gila monstor), lions (mountain lion), black bears, wolf (coyotes), wild boar (javelina), and even scorpion
  • better to have a fuel economic vehicle: Jeep
  • Dynamic temperature – can be hot and cold
  • possible suffer from sun burn, and dry skin
  • near Mexico : so we can enjoy Mexican food as well

 

US Official weather service – National Weather Service

NWS Phoenix (weather.gov)

2021 AZ
2022 AZ
2023 AZ

2021 – 2023 AZ average temperature : 76.5°F = 24.7 °C

However, in 2023, the average highest temperture recorded as high as 102.7 °F = 39.3 °C 

The lowest average temperature over the past three years was recorded in 2023 as well : 53.9 °F = 12.1 °C 

Additionally, the minimum temperature recorded on 24 Jan 2023 was only 35 °F  = 1.6 °C

 

Wet winter in Phoenix – affected by El Nino

 

Snowfall in Phoenix 

 

Drought in Arizona

 

Monsoon in Arizona

Monsoon in Arizona – Tommy’s Diaries (tommykwan.com)

 

 

 

Adelaide

Adelaide in 2023 (bom.gov.au)

Greater Adelaide in 2023

Rainfall

  • Rainfall totals for 2023 were close to average or above average at sites across Adelaide and the Hills.
  • Rainfall totals for 2023 ranged from 98% of average at Edinburgh RAAF, Mount Crawford AWS, and Mount Lofty to 117% of average at Noarlunga.
  • For Greater Adelaide as a whole, rainfall totals in 2023 were less than in 2022, but more than in 2021.
  • June and December were much wetter than average months for Greater Adelaide, with numerous sites having their wettest June or December day on record respectively.
  • After a dry first half of November, severe thunderstorms crossed Greater Adelaide on 27–28 November, bringing strong winds, heavy rain and flash flooding, with McLaren Vale (Pirramimma Winery) and Brownhill Creek (Scotch College) having their highest daily rainfall on record.

Temperature

  • Mean maximum temperatures for 2023 were close to average or warmer than average across Adelaide and the Hills.
  • Mean maximum temperatures ranged from 0.5 °C cooler than average at Kuitpo Forest Reserve to 1.2 °C warmer than average at Mount Lofty.
  • Maximum temperatures were cooler than average in May, but were much warmer than average in September.
  • Mean minimum temperatures for 2023 were close to average or warmer than average across Adelaide and the Hills.
  • Mean minimum temperatures ranged from 0.2 °C cooler than average at Mount Crawford AWS and Noarlunga to 1.2 °C warmer than average at Mount Barker.

Adelaide (West Terrace / ngayirdapira)

  • Total rainfall for Adelaide (West Terrace / ngayirdapira) was 587.6 mm, which is 111% of the long-term average of 527.8 mm.
  • The mean daily maximum temperature for Adelaide (West Terrace / ngayirdapira) was 22.3 °C, which is 0.5 °C above the long-term average of 21.8 °C.
  • The warmest day was 40.6 °C on 14 January, and the coolest day was on 27 June when the temperature reached 12.2 °C.
  • The mean daily minimum temperature for Adelaide (West Terrace / ngayirdapira) was 12.2 °C, which is 0.2 °C above the long-term average of 12.0 °C.
  • The coldest morning was 2.9 °C on 18 July, and the warmest morning was on 24 February when the minimum temperature was 29.6 °C.

About Australian Climate (bom.gov.au)

wpChatIcon