BARD PAPER: GAIL4020

Habitable Zone Temperature Chart

by Pete Gray

This is a unified chart for determining the surface temperatures for habitable zone worlds with breathable atmospheres around main sequence stars. All listed temperatures are in degrees Centigrade. These are averages, and do not reflect additional details such as rotation period and axial tilt. And they are applicable only to inland areas more than a hundred kilometers from any sizeable body of water. This is for more than chrome, unless your players enjoy skiing in their swimtrunks.

All of the following data was calculated by the use of zone charts and temperature formula in World Builders Handbook.

As you can see from the following charts, different circumstances in atmosphere and stellar type can have major differences for sentient comfort. And worlds with a hydrosphere code of less than 5 are rarely comfortable. The coolest star types are the M0V and K0V, and the K5V is the hottest.

Atmosphere 4-5
Hyd Stellar
F0V F5V G0V G5V K0V K5V M0V
0 84.0 109.2 87.4 107.8 69.0 144.8 81.6
1 84.0 109.2 87.4 107.8 69.0 144.8 81.6
2 78.0 92.7 70.9 90.7 53.8 127.1 76.7
3 78.0 92.7 70.9 90.7 53.8 127.1 76.7
4 51.7 75.2 64.0 73.4 38.8 108.0 50.5
5 35.1 52.5 46.8 55.7 21.1 89.8 35.0
6 20.3 41.6 31.5 50.8 8.2 71.3 19.3
7 4.5 24.6 15.1 23.2 -7.0 52.7 3.5
8 -11.4 7.6 -1.4 6.3 -22.2 34.1 -12.3
9 -27.1 -9.6 -18.0 -10.9 -44.6 15.2 -28.3
A -27.1 -9.6 -18.0 -10.9 -44.6 15.2 -28.3

**Atmosphere 4-5**
Hyd				Stellar
	F0V	F5V	G0V	G5V	K0V	K5V	M0V
0	84.0	109.2	87.4	107.8	69.0	144.8	81.6
1	84.0	109.2	87.4	107.8	69.0	144.8	81.6
2	78.0	92.7	70.9	90.7	53.8	127.1	76.7
3	78.0	92.7	70.9	90.7	53.8	127.1	76.7
4	51.7	75.2	64.0	73.4	38.8	108.0	50.5
5	35.1	52.5	46.8	55.7	21.1	89.8	35.0
6	20.3	41.6	31.5	50.8	8.2	71.3	19.3
7	4.5	24.6	15.1	23.2	-7.0	52.7	3.5
8	-11.4	7.6	-1.4	6.3	-22.2	34.1	-12.3
9	-27.1	-9.6	-18.0	-10.9	-44.6	15.2	-28.3
A	-27.1	-9.6	-18.0	-10.9	-44.6	15.2	-28.3

Atmosphere 6-7
Hyd Stellar
F0V F5V G0V G5V K0V K5V M0V
0 101.0 128.0 113.1 125.9 85.3 165.6 100.6
1 101.0 128.0 113.1 125.9 85.3 165.6 100.6
2 84.2 100.1 96.2 107.1 69.4 146.2 82.9
3 84.2 100.1 96.2 107.1 69.4 146.2 82.9
4 53.4 91.8 80.1 90.1 52.4 136.2 53.0
5 38.6 73.1 62.0 71.4 35.9 105.7 38.5
6 23.1 54.4 46.0 55.0 22.6 87.6 21.0
7 7.3 37.2 28.8 37.3 5.7 68.2 6.3
8 1.1 21.0 11.5 21.6 -9.3 48.7 0.1
9 -24.9 3.0 -5.9 1.6 -26.3 39.0 -26.6
A -24.9 3.0 -5.9 1.6 -26.3 39.0 -26.6

**Atmosphere 6-7**
Hyd				Stellar
	F0V	F5V	G0V	G5V	K0V	K5V	M0V
0	101.0	128.0	113.1	125.9	85.3	165.6	100.6
1	101.0	128.0	113.1	125.9	85.3	165.6	100.6
2	84.2	100.1	96.2	107.1	69.4	146.2	82.9
3	84.2	100.1	96.2	107.1	69.4	146.2	82.9
4	53.4	91.8	80.1	90.1	52.4	136.2	53.0
5	38.6	73.1	62.0	71.4	35.9	105.7	38.5
6	23.1	54.4	46.0	55.0	22.6	87.6	21.0
7	7.3	37.2	28.8	37.3	5.7	68.2	6.3
8	1.1	21.0	11.5	21.6	-9.3	48.7	0.1
9	-24.9	3.0	-5.9	1.6	-26.3	39.0	-26.6
A	-24.9	3.0	-5.9	1.6	-26.3	39.0	-26.6

Atmosphere 8-9
Hyd Stellar
F0V F5V G0V G5V K0V K5V M0V
0 118.0 146.2 132.7 142.1 101.6 185.6 116.4
1 118.0 146.2 132.7 142.1 101.6 185.6 116.4
2 100.5 127.5 114.6 125.4 85.0 165.2 98.1
3 100.5 127.5 114.6 125.4 85.0 165.2 98.1
4 82.6 108.4 96.1 106.5 63.5 143.3 81.4
5 64.0 88.9 77.2 87.1 50.0 119.4 63.2
6 50.9 71.5 60.5 70.9 34.6 104.0 47.2
7 30.9 53.0 42.5 51.4 18.0 83.7 29.9
8 13.5 34.3 24.5 32.9 0.7 61.3 12.5
9 -3.9 15.5 6.3 14.1 -15.4 23.9 -4.9
A -3.9 15.5 6.3 14.1 -15.4 23.9 -4.9

**Atmosphere 8-9**
Hyd				Stellar
	F0V	F5V	G0V	G5V	K0V	K5V	M0V
0	118.0	146.2	132.7	142.1	101.6	185.6	116.4
1	118.0	146.2	132.7	142.1	101.6	185.6	116.4
2	100.5	127.5	114.6	125.4	85.0	165.2	98.1
3	100.5	127.5	114.6	125.4	85.0	165.2	98.1
4	82.6	108.4	96.1	106.5	63.5	143.3	81.4
5	64.0	88.9	77.2	87.1	50.0	119.4	63.2
6	50.9	71.5	60.5	70.9	34.6	104.0	47.2
7	30.9	53.0	42.5	51.4	18.0	83.7	29.9
8	13.5	34.3	24.5	32.9	0.7	61.3	12.5
9	-3.9	15.5	6.3	14.1	-15.4	23.9	-4.9
A	-3.9	15.5	6.3	14.1	-15.4	23.9	-4.9

For quick reference the following temperature guide, adapted from GURPS Traveller: Behind the Claw is included. Temperature is listed as both in Centigrade/Fahrenheit format

Temp Code Average Temp Description
Very Hot 48.8/120 Summer in Death Valley
Hot 43.3/110 Summer in Phoenix
Tropical 37.8/100 Summer in East Africa
Warm 32.2/90 Summer in East Texas
Normal 26.7/80 Spring in Los Angeles
Cool 15.6/60 Spring in Toronto
Chilly 4.4/40 Fall in London
Cold -6.7/20 Winter in Berlin
Very Cold -17.8/0 Winter in Toronto
Freezing -28.9/-20 Winter in Fairbanks

Temp Code	Average Temp	Description
Very Hot	48.8/120	Summer in Death Valley
Hot	43.3/110	Summer in Phoenix
Tropical	37.8/100	Summer in East Africa
Warm	32.2/90	Summer in East Texas
Normal	26.7/80	Spring in Los Angeles
Cool	15.6/60	Spring in Toronto
Chilly	4.4/40	Fall in London
Cold	-6.7/20	Winter in Berlin
Very Cold	-17.8/0	Winter in Toronto
Freezing	-28.9/-20	Winter in Fairbanks