双点计算器
找到从空气温度和相对湿度 找到露点, 并给人一个舒适的评级。
输入结果时更新 。
关于此计算器
The dew point is the temperature to which air must be cooled for its water vapour to start condensing into dew, and it is the most honest single measure of how much moisture the air actually holds. A higher dew point means more water in the air and a muggier, stickier feel; it is also the temperature at which fog forms, grass gets damp overnight and a cold drink beads with condensation. This dew point calculator derives it from the air temperature and the relative humidity you enter.
It uses the Magnus-Tetens approximation with the Alduchov-Eskridge coefficients (a = 17.625, b = 243.04 °C): first γ = ln(RH / 100) + aT / (b + T), then the dew point = bγ / (a − γ), with T in °C. As a worked example, air at 25 °C and 60% relative humidity has a dew point of about 16.7 °C — comfortable edging toward sticky. Drop the humidity to 30% at the same 25 °C and the dew point falls to roughly 6 °C, distinctly dry. The method is accurate to within a few tenths of a degree across ordinary weather, and the tool works in either °C or °F.
Dew point predicts comfort far better than relative humidity, because relative humidity depends on temperature: 90% humidity on a cold morning feels dry, while 60% on a hot afternoon feels oppressive. As an absolute measure, dew point cuts through that — below about 13 °C (55 °F) feels comfortable, 16–18 °C (60–65 °F) starts to feel sticky, and above 21 °C (70 °F) is oppressive and hard to cool down in. The same value tells you when condensation will form on windows, pipes and aircraft surfaces.
经常问到的问题
露点使用什么公式?
与Alduchov-Eskridge常数的Magnus-Ttens近似值: Q = In(RH/100) + 17.625.T/(243.04+T), 露点 = 243.04/(17.625+T), T在°C。 准确的说,比正常天气条件高出十分之一的几分之一。
为什么露点比湿度更重要?
相对湿度取决于温度,因此10°C的湿度90%感到干燥,30°C的湿度60%感到干燥。 下点是水分的绝对量度,因此它跟踪空气的粘性如何真正感觉更好。
哪个露点感觉舒服?
约13°C(55°F)以下的温度感到舒适和干燥,16-18°C(60-65°F)开始感到粘糊,21°C(70°F)以上是压抑性的,很难降温。
露水点会不会比空气温度高?
否。 最多是露点等于空气温度,当空气完全饱和时,温度为100%相对湿度。任何冷却器和蒸汽浓缩器,因此露点总是在或低于当前温度。
露水点与雾和露水的形成有何关系?
当表面或空气凉到露点时,蒸汽凝结——即当露在草上、雾状和冷玻璃上的凝结珠上时,接近夜间低点的露点可能是好迹象雾或露。
当温度变化时, 露点会改变吗?
露水点不是单方的,而是实际的湿度含量,它作为空气温暖或冷却状态,保持不变。 温度的变化是相对湿度,这就是为什么露水点是更稳定的气压测量。
使用 Magnus-Tetens 公式的准确度如何?
以阿尔杜丘夫-埃斯克里奇系数计算,准确的说,在正常天气温度和潮湿范围中,每秒摄氏摄氏度以十分之一的幅度内,这完全符合日常湿度读数的精确度。
API - 使用代码中的计算器
将此计算器称为自由 JSON 端点 。 不需要按键 。 将字段值发送到下面作为查询参数或 JSON 。 任何您省略的, 都会使用相同的默认值, 此页面预填的默认值是预填的; 未知参数是 400, 而不是静音零 。 读取 API 全部文件 →
终点
GET https://calculator.free/api/v1/dew-point/curl
curl "https://calculator.free/api/v1/dew-point/?units=c&temp=25&humidity=60"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/dew-point/?" + new URLSearchParams({
"units": "c",
"temp": "25",
"humidity": "60"
}));
const data = await r.json();
console.log(data.results);成果仅是一般指导的估计数,而不是财务、医疗或税务咨询。