Heat index (Celsius)

Relative humidity (%)	Temperature (°C)
Relative humidity (%)	27	28	29	30	31	32	33	34	36	37	38	39	40	41	43	47
40	27	27	28	29	31	33	34	36	38	41	43	46	48	51	54	58
45	27	28	29	31	32	34	36	38	40	43	46	48	51	50	58
50	27	28	29	31	33	35	37	39	42	45	48	51	55	58
55	27	29	30	32	34	36	38	41	44	47	51	54	58
60	28	29	31	33	35	38	41	43	47	51	54	58
65	28	29	32	34	37	39	43	46	49	53	58
70	28	30	32	35	38	41	46	48	52	57
75	29	31	33	36	39	43	47	51	56
80	29	32	34	38	41	45	49	54
85	29	32	36	39	43	47	52	57
90	30	33	37	41	45	50	55
95	30	34	38	42	47	53
100	31	35	39	44	49	56

Likelihood of heat disorders with prolonged exposure or strenuous activity
	Caution				Extreme caution				Danger				Extreme danger

Data from: Jacklitsch B. Heat Index: When humidity makes it feel hotter. NIOSH Science Blog. Centers for Disease Control and Prevention. Available at: https://blogs.cdc.gov/niosh-science-blog/2017/06/05/heat-index/ (Accessed on August 25, 2021).

Graphic 133127 Version 1.0