Heat
Index
Calculator

Calculate heat index (feels-like temperature) from air temperature and humidity with NWS danger level classification.

Unit System

Temperature (F)

Humidity (%)

Heat Index

99.7 F

Extreme Caution

NormalCautionExtreme CautionDangerExtreme

Danger LevelExtreme Caution

Feels Like vs Actual99.7 F

Temp / RH	40%	45%	50%	55%	60%	65%	70%	75%	80%	85%	90%	95%	100%
80 F	80	80	81	81	82	82	83	84	84	85	86	86	87
82 F	81	82	83	84	84	85	86	88	89	90	92	94	96
84 F	83	84	85	86	88	89	90	92	94	96	98	101	104
86 F	85	87	88	89	91	93	95	97	100	102	105	109	112
88 F	88	89	91	93	95	98	100	103	106	110	113	117	121
90 F	91	92	95	97	100	103	106	109	113	117	122	127	132
92 F	94	96	99	101	105	108	112	116	121	126	131	137	143
94 F	97	100	103	106	110	114	119	124	129	135	141	148	155
96 F	101	104	108	112	116	121	126	132	138	145	152	160	168
98 F	105	109	113	117	123	128	134	141	148	155	164	172	181
100 F	109	114	118	124	129	136	143	150	158	167	176	185	195
102 F	114	119	124	130	137	144	152	160	169	179	189	199	210
104 F	119	124	131	137	145	153	161	171	181	191	202	214	226
106 F	124	130	137	145	153	162	172	182	193	204	216	229	243
108 F	130	137	144	153	162	172	182	193	205	218	231	245	260
110 F	136	143	152	161	171	182	194	206	219	233	247	262	278

HeatIndexCalculator