数据说明

阴影下气温：气象站实测空气温度（℃），即日常天气预报温度。

阳光下气温：按直接太阳辐射折算的等效气温，仅用于估算阳光下炎热指数，非实测温度。文献记载全日照可使热指数升高约 8–10℃（NWS 称 up to 15°F≈9℃），本页据此保守修正。

炎热指数 (HI)：美国 NWS/Rothfusz 体感温度公式，综合气温与相对湿度。公式仅对气温 ≥26.7℃（80°F）有效（Anderson et al., 2013），本页按 NWS 官方算法加入低湿度与温和区间修正。

• <27℃：舒适 / 凉爽
• 27–32℃：注意 · 长时间活动可能疲劳
• 33–39℃：警惕 · 热痉挛、热衰竭风险升高
• 40–51℃：危险 · 热相关疾病风险高
• ≥52℃：极度危险 · 中暑风险极高，应避免户外活动

数据来源：Open-Meteo（免费）。炎热指数按 NWS 定义针对"阴凉、轻风"环境，风速不参与计算；如需更严谨地纳入太阳辐射与风速，可参考 WBGT（ISO 7243）或 UTCI。当气温低于 26.7℃ 时不计算炎热指数，直接显示气温。

参考文献

1. Rothfusz LP. The Heat Index "Equation" (or, More Than You Ever Wanted to Know About Heat Index)[R]. NWS Technical Attachment SR 90-23. Fort Worth: NOAA/National Weather Service, 1990.
2. Anderson GB, Bell ML, Peng RD. Methods to calculate the heat index as an exposure metric in environmental health research[J]. Environmental Health Perspectives, 2013, 121(10): 1111-1119. DOI: 10.1289/ehp.1206273.
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11. ISO 7243. Hot environments - Estimation of the heat stress on working man, based on the WBGT-index (wet bulb globe temperature)[S]. Geneva: International Organization for Standardization, 1989.
12. ISO 7726. Ergonomics of the thermal environment - Instruments for measuring physical quantities[S]. Geneva: International Organization for Standardization, 1998.