My phone is set to Fahrenheit, so I at least know what temp it actually is when the news talked about it.
It's not quite accurate, but I usually remember it by knowing that 10 C = 50 F and then approximating that for each 5 Celsius higher, you add about 10 to the Fahrenheit number, and each 5 lower you subtract 10:
- 5 C = 20 F (actual is 23 F)
0 C = 30 F (actual is 32 F)
5 C = 40 F (actual is 41 F)
10 C = 50 F (exact conversion)
15 C = 60 F (actual is 59 F)
20 C = 70 F (actual is 68 F)
25 C = 80 F (actual is 77 F)
30 C = 90 F (actual is 86 F)
35 C = 100 F (actual is 95 F)
Looking at the numbers, it's actually a difference of 9 F between each one, but 10 is easier to remember.