Heat Index
  Dew Point (F)
Temp (F) 50 55 60 65 70 75 80 85
65 63 64 65 67        
70 68 69 70 71 73      
75 73 74 75 76 79 81    
80 80 81 82 83 84 87 91  
85 84 85 86 88 91 94 99 107
90 88 89 91 94 97 101 107 116
95 93 95 97 100 103 108 115 124
100 98 100 102 106 110 115 123 132
105 103 105 108 112 116 122 130 140
110 109 111 114 118 122 128 136 147
  Relative Humidity (%)
Temp (F) 90 80 70 60 50 40 30 20 10
65 66 65 64 63 62 61 60 59 58
70 72 71 70 69 68 67 66 65 64
75 80 77 76 75 74 73 72 71 70
80 88 86 84 83 82 80 79 77 76
85 101 97 93 90 88 86 84 82 80
90 119 112 106 101 96 92 89 87 84
95 142 131 122 114 107 101 96 92 89
100 169 154 141 130 120 111 104 99 94
105 200 181 163 148 135 123 114 106 100
110 236 211 189 169 152 137 124 114 106
115 275 245 218 193 171 152 136 122 112
120 319 283 250 220 193 169 149 132 118
Any value less than 80 is considered comfortable.
Any value greater than 90 is considered extreme.
Any value greater than 100 is considered hazardous.
Any value greater than 110 is considered dangerous.
90 to 105: Heat stroke possible with prolonged exposure
105 to 130: Heat stroke likely with prolonged exposure
130 or above: Heat stroke highly likely with continued exposure