−39 °F at a glance
- Celsius
- −39.44 °C
- Exact fraction
- −39 4/9 °C
- Kelvin
- 233.71 K
- Rankine
- 420.67 °R
- Rounded
- −39 °C
- Quick estimate
- −34.5 °C
How to convert −39 °F to Celsius
(−39 − 32) × 5/9 = −71 × 5/9 = −355/9 = −39.44 °C
Subtract 32 first because the two scales put zero in different places, then multiply by 5/9 because a Fahrenheit degree is only 5/9 the size of a Celsius degree. −71 is not a multiple of 9, so the exact answer is the repeating decimal −39 4/9 °C.
Estimate it in your head
Subtract 30 and halve: (−39 − 30) ÷ 2 = −34.5 °C. That is 4.9 degrees high — the shortcut drifts at very hot and very cold temperatures, so use the exact formula there.
What −39 °F feels like
Below zero Fahrenheit, wind matters more than the thermometer. The National Weather Service wind chill index estimates how cold −39 °F feels on exposed skin; once the wind chill reaches about −18 °F (−28 °C), frostbite can set in within 30 minutes.
| Wind | Feels like | In °C | Note |
|---|---|---|---|
| 10 mph | −64 °F | −53 °C | Frostbite possible in 30 min or less |
| 20 mph | −73 °F | −58 °C | Frostbite possible in 30 min or less |
| 30 mph | −79 °F | −62 °C | Frostbite possible in 30 min or less |
At −39.44 °C even a home freezer (0 °F) would feel warm. Car batteries lose much of their cranking power, diesel fuel can gel without additives, and pipes in unheated spaces are at real risk.
Temperatures near −39 °F
| Fahrenheit | Celsius | Kelvin |
|---|---|---|
| −40 °F | −40 °C | 233.15 K |
| −39 °F | −39.44 °C | 233.71 K |
| −38 °F | −38.89 °C | 234.26 K |
| −37 °F | −38.33 °C | 234.82 K |
| −36 °F | −37.78 °C | 235.37 K |
| −35 °F | −37.22 °C | 235.93 K |
| −34 °F | −36.67 °C | 236.48 K |
Going the other way: −39 °C in Fahrenheit is −38.2 °F.
Frequently asked questions
What is −39 °F in Celsius?
−39 °F is −39.44 °C: subtract 32 (−71) and multiply by 5/9.
Is −39 °F hot or cold?
−39 °F is severe cold, 39.0 degrees below zero Fahrenheit and well below freezing.
How do you convert −39 °F to Celsius in your head?
Subtract 30 and divide by 2: (−39 − 30) ÷ 2 = −34.5 °C, compared with the exact −39.44 °C.
What is −39 °F in Kelvin?
−39 °F is 233.71 K. Convert to Celsius (−39.44 °C) and add 273.15.