ミリッサ 12月の天気
ミリッサの12月:猛暑、大雨続き、蒸し暑い — 雨の日21日が気にならなければ悪くない時期。
2026年9月更新 · ERA5再解析による気候平年値
ミリッサでは12か月中7位 · 12月に訪れたい旅行先で1413か所中522位 · 快適スコア78/100(Bランク)
- 日中
- 30°C
- 夜
- 24°C
- 雨の日
- 21
- 日照
- 9.7 h
- 湿度
- 85%
- 日の長さ
- 12 h

12月のミリッサについての旅行者の声
近くのゴールからのメモ(30 km)
ミリッサには12月のメモがまだありません — これは季節を共にする近くのゴールについてのメモです。
December is the month the south-west coast changes over, and regulars put the turn late rather than early: the coast dries out a lot from mid-December, and the season proper starts just before Christmas. Some years the first half stays very wet, and they report Decembers where it rained throughout, or where the dry days still carried a sea too rough and windy to enjoy until January. Our row reads that first half: 186.2mm across 21.8 precipitation days, the wettest in this batch. Heat is steady at 30.1C reading as 36C at 84 percent humidity, with a 28.6C sea. For the most reliable south-coast beach weather they name February and March instead. The record: 9.6 hours of sun, a 10.6 kph wind and AQI 57.
ミリッサのほかの月
Mirissa-forum threads on April weather call it the last reliably good month on the south coast before the monsoon takes over - calm seas still holding for swimming and beginner surfing, though posters describe it as a genuine shoulder season where conditions can start slipping outside the reef-protected stretches of beach. Showers become more likely after the middle of the month, roughly a month ahead of when the real southwest monsoon breaks, typically arriving as a short afternoon or evening burst rather than an all-day soak. Regulars still rate plenty of sunshine across most days, humidity climbing but not yet unbearable. The standing advice is to front-load a south-coast beach stay for the first half of April if a trip's dates are flexible, since the back half carries noticeably higher odds of a wet afternoon. The record: 31.2C days feeling like a punishing 38C, 25.6C nights, a notably high 169mm across 25.6 days, 85 percent humidity, a 30.3C sea and 10.5 hours of sun.
Mirissa-forum threads on November weather place it inside the second inter-monsoon season - genuinely the wettest stretch of the year by rainfall total, and posters call conditions unsettled rather than predictable week to week. The one consistent pattern regulars point to: rain tends to arrive later in the day, leaving mornings sunny more often than the wet-season reputation implies, and the island still logs real total sunshine across the month. Sea conditions are the bigger practical concern - not calm enough most days for swimming on the open coast, though a few sheltered stretches of beach stay swimmable. Regulars steer visitors wanting reliable beach weather toward January through mid-March instead. The record: 29.6C days feeling like a sticky 35C, 24.4C nights, a notably high 306mm across 25.1 days, 87 percent humidity, an 8.8-hour sun day and a 29.3C sea - the wettest entry on Mirissa's whole calendar.
Hikkaduwa-and-Mirissa forum threads on July weather describe the south coast as manageable through the off-season rather than ideal: decent conditions most days, but evening showers are common and the sea runs genuinely rough, making swimming and snorkeling harder than in the calmer months. Mirissa gets called out specifically for having reef-protected sections of beach that stay swimmable even when the open coast doesn't, a real edge over neighboring beaches this time of year. Posters describe a reliable pattern - good weather most mornings, showers arriving later in the day in short bursts rather than settling in for hours. The record: 29.2C days feeling like a sticky 33C, 25.6C nights, 140mm across a notably high 25.4 days, an 85 percent humidity, a 26.5C sea and 10.5 hours of sun - the wettest, roughest entry on this destination's whole calendar, exactly matching the off-season framing.
January is the start of the good half of Mirissa's whale season: the south coast runs November to May, and regulars say sightings improve into January and February, which is the window they name for blue whales. Two practical points come with it. The boats leave early - reporting around half past six for a seven o'clock start, three and a half to four hours out - which is the reason to stay in Mirissa rather than Galle or Colombo. And the weather is not settled at the turn of the year: rain can hang on into mid-January, with the first half of the day the reliable part on this coast. Our row's 133.8mm across 16.3 days is that. The record: 30C days that feel like 36C, 23.8C nights, humidity 82 percent and a 27.6C sea.
地図のミリッサのカードから自分のメモを追加できます。
ミリッサの気候平年値 — 12月
ERA5再解析による月平均値です。AQIはその月の平均US AQI(米国大気質指数)です。
12月のミリッサの混雑
その場所自体の混み具合 — 学校休暇や大型連休、編集部がタグ付けした月、そして天気の良さによる人気の高さ。快適スコアには含まれません。
ピークの混雑South coast surf season、Christmas and New Year peak、スリランカのYear-end break(推定)
ピークの混雑混雑ショルダーシーズン閑散
ミリッサの天気が良い月
この旅行先自身の一年間の快適スコアでランキングしています — 混み具合とは別のものです(上の「混雑」を参照)。
天気はまずまずミリッサの天気がピークを迎えるのは1月〜3月で、特に良いのは2月ごろです。
天気が最高天気はまずまず天気が厳しい
12月のミリッサのイベント
毎年の季節のイベント、自然の見どころ、休業、祝日 — 厳選し出典を明記しています。
- 自然
Blue whale season
11月1日〜4月15日早めの予約をBoats leave the harbour before dawn for the shelf edge an hour or two out, and sightings are close to routine between December and March. Pick an operator that keeps its distance; plenty do not.
- 季節
South coast surf season
11月1日〜4月15日混雑The clean swell is round the corner at Weligama, which is where every board hire and beginner lesson on this stretch happens. Mirissa's own bay is for swimming rather than surfing.
- 祝日
Christmas and New Year peak
12月20日〜1月5日クリスマス・年末年始混雑早めの予約をThe fortnight the beach bars run parties and rooms behind the sand cost triple what they do in November. The whale boats sell out the night before rather than the week before. 出典 ↗
近くで開催中のイベント
ミリッサから300 km以内 — 日帰りやちょっとした移動で行けて、今月何かがある場所です。快適スコアには含まれません。
ミリッサはどこにある?
12月のミリッサ — よくある質問
- 12月はミリッサを訪れるのに良い時期ですか?
- ミリッサの12月:猛暑、大雨続き、蒸し暑い — 雨の日21日が気にならなければ悪くない時期。SeasonMapの快適スコアでは、ミリッサの12か月中7位です(78/100)。
- 12月のミリッサはどんな天気ですか?
- 12月のミリッサは、平均最高気温29.9°C、最低気温24.1°C、降水量は約180.1 mmで、雨の日はおよそ21日です。
- 12月のミリッサの大気質はどうですか?
- 12月のミリッサの米国大気質指数(US AQI)は、平均約57です。
300 km圏内:Nuwara EliyaのAdam's Peak pilgrimage season(12月5日〜5月10日ごろ)、ColomboのBlue whales off Mirissa(11月1日〜4月15日ごろ)。