ニューヨークの月別の天気

There has been a pronounced local warming trend in New York City since the 1990s, but the climate is still temperate, except in the summer. Due to its proximity to the humid continental climate zone of the north, it generally experiences all four seasons, with hot and humid summers (Jun-Sept), mild to cool falls (Sept-Nov), mild to very cold winters (Dec-Mar), and increasingly mild, wet springs (Mar-Jun). Average highs for January are around 38°F (3°C) and average highs for July are about 84°F (29°C). However, temperatures in the winter can go down to as low as 0°F (-18°C), although periods of sustained extreme cold with highs in the teens or low 20s for two weeks or more are increasingly a thing of the past, whereas what used to be freakish temperatures in the 70s in midwinter are increasingly common, and in the summer, temperatures can go above 100°F (38°C).…

New York's forum puts January in the 30s°F on average with a handful of days dipping into the teens, and wind funneling between skyscrapers making it feel colder than the thermometer says. Regulars note the city sees measurable precipitation on about 13 days this month — more often cold rain or sleet than accumulating snow — and that hotel rates and crowds both drop noticeably after the New Year rush.

New York forum regulars call April one of the year's most volatile months, if less extreme than March: “never really predictable,” with daytime highs in the 50s-60s°F and lows in the 40s typical, but “not uncommon for winter to make an appearance, especially early in the month.” The comparison offered for calibration: “March is generally colder, and April is generally wetter,” though neither very cold nor very hot, which regulars call a genuinely agreeable trade. Standard advice is a warmer jacket plus a sweater or hoodie to layer, and rain gear regardless of forecast. The payoff: trees budding, flowers blooming, spring in full swing by month's end. Our record: 15.7°C days, 6.4°C nights, 11.8 rain days and a 19.6kph wind — mild with real rain frequency, matching the unpredictable-but-agreeable read.

New York-forum threads on May weather agree on one thing: it's a toss-up. Regulars describe afternoons landing anywhere from the mid-60s to the 80s Fahrenheit within the same week, with mornings still cool enough for a jacket, and the standing advice is to pack layers plus a compact rain shell rather than trust any single forecast. The month is rated genuinely pretty once the sun is out - parks green, before summer's humidity sets in. May's record: 21.7C days, 12.7C nights, 105mm of rain across ten days, 9.3 hours of sun and an AQI of 57.

New York regulars on the forum call June the favorite of the summer months — warm, long days, and the real humidity most visitors dread doesn't reliably show up until July. The one universal tip: bring a layer for indoors, the AC runs cold.

Forum verdict on July: "brutally hot and sticky" and "the luck of the draw" on how bad both get. The heat itself isn't what people complain about — it's heat plus the walking and stair-climbing the city demands. The detail that comes up again and again is subway platforms: the trains are air-conditioned, the platforms are not, and one poster was "sweltering and sticky in seconds" waiting for one. Regulars plan around it rather than through it — a shower and a change of clothes back at the hotel in the late afternoon, because "the humidity can really sap energy." Several suggest dodging the last two weeks of July and the first two of August specifically. One visitor used to Midwest summers wrote simply: "Never again." Our record has 29.5°C highs and 21°C nights in July, which is the part people underrate — it doesn't cool off.

New York-forum threads on September weather call it a genuinely pleasant stretch, warm without August's worst humidity, though posters are consistent the month is hard to pin down more than a few days out - a run of crisp, sunny days can flip to a muggy, sticky one with little warning. Hurricane season technically runs through the month, worth a glance at the forecast even though direct hits on the city are rare. The standing packing advice is layers plus a compact rain jacket with a hood, since a passing shower can arrive without much warning. Regulars call it one of the more reliable shoulder-season windows for walking tours and rooftop time alike. The record: 24.9C days feeling like 26C, 17.4C nights, 124mm across 7.3 days, a 22.2C sea, 75 percent humidity and 8.7 hours of sun.

October is New York at its best and I'll argue with anyone: 18°C, blue sky, the park turning, no humidity. Early October still gets warm afternoons; by the end you want a proper coat at night.

The forum's December picture for New York: cold to very cold, with rain as likely as snow — first flakes average around 15 December, and early December has almost no odds of any. Christmas week improves the snow chances but often delivers rain or plain dry cold instead. On crowds the regulars are more precise than you would expect: tourist numbers are very high at the start of December, there is a sweet spot mid-month while school is still in, and Midtown, Rockefeller Center and the shopping streets are the pinch points. Pack a hat, gloves and scarf you can strip off — indoors is always overheated.