just learned easy approx. Celsius > Fahrenheit

[Stig / Major Tom]

It's not precise - but close enough for govt. work.

Take the Celsius figure and double it - then add 30.
2°C X 2 = 4
4 + 30 = 34°F   (actual 35.6°F - but close enough

100°F to Celsius

100 - 30 = 70
divide 70 by 2 = 35°C  (37.7°C actual)

Again - gets us in the ballpark when those foreigners tell us they're nearly dead at 45°C ~!

"anything for dummies!"
    is my go-to

Stig

[rjs987]

20 years ago I wrote a program to translate Fahhrenheiit to Celsius and the other way also. That was before such was easily found on the Internet for quick translation as it is now. I even included checks for the absolute minimum temp possible. Since then I always remember that every 9 deg F is another 5 deg C. I actually always knew this but after writing that program I didn't have to think about it anymore. I just have to remember where to start. I usually start at 32F = 0C and go from there.
-13F = -25C
-4F = -20C
5F = -15C
14F = -10C
23F = -5C
32F = 0C
41F = 5C
50F = 10C
59F = 15C
68F = 20C
77F = 25C
86F = 30C
95F = 35C
104F = 40C

This is the entire range of temps that I currently ride in. Though I'm beginning to question that first lowest temp for riding as I get older.
My ideal riding temp is 77F (25C). Notice that 68F to 86F (numbers reversed) is 20C to 30C.
Just a few thoughts that make it easy for me to remember and translate on the fly. If I can remember the increments I can easily guess in between temps close enough.

[randyo]

or x 9/5 + 32 and get the exact conversion

[Stig / Major Tom]

or x 9/5 + 32 and get the exact conversion

Randy, true enough
but I need easy/quick - or my interest fades!

Stig

[randyo]

that is pretty much my temp range as well, for a real ride (min.100 miles), although I meandered one day from Joplin, MO to Vivian, LA and saw 110° +, my coldest wasn't a real ride, just a test spin up to the corner & back, total 1 mile, -25°f  COLD AIR = FREE HORSEPOWER, other than that, a ride around the pond (Lake Winnipesaukee) at -15°f  on my little red nekid '99 SV650.   

20 years ago I wrote a program to translate Fahhrenheiit to Celsius and the other way also. That was before such was easily found on the Internet for quick translation as it is now. I even included checks for the absolute minimum temp possible. Since then I always remember that every 9 deg F is another 5 deg C. I actually always knew this but after writing that program I didn't have to think about it anymore. I just have to remember where to start. I usually start at 32F = 0C and go from there.
-13F = -25C
-4F = -20C
5F = -15C
14F = -10C
23F = -5C
32F = 0C
41F = 5C
50F = 10C
59F = 15C
68F = 20C
77F = 25C
86F = 30C
95F = 35C
104F = 40C

This is the entire range of temps that I currently ride in. Though I'm beginning to question that first lowest temp for riding as I get older.
My ideal riding temp is 77F (25C). Notice that 68F to 86F (numbers reversed) is 20C to 30C.
Just a few thoughts that make it easy for me to remember and translate on the fly. If I can remember the increments I can easily guess in between temps close enough.

[Neil955i]

It's not precise - but close enough for govt. work.

Take the Celsius figure and double it - then add 30.
2°C X 2 = 4
4 + 30 = 34°F   (actual 35.6°F - but close enough

100°F to Celsius

100 - 30 = 70
divide 70 by 2 = 35°C  (37.7°C actual)

Again - gets us in the ballpark when those foreigners tell us they're nearly dead at 45°C ~!

"anything for dummies!"
    is my go-to

Stig

So today we’re promised 15C (yes, really!) so that’s approximately 60F?

[Stig / Major Tom]

So today we’re promised 15C (yes, really!) so that’s approximately 60F?

no words.....



Major Tom

[CROSSBOLT]

That's neat, Stig! I wonder if my Subaru Crosstrek has a C to F button...Har, har!

[Neil955i]

I was taught metric measurements in school when the vast majority of the UK was still happily measuring in weight by lbs & ozs and paying in £so! 240d to the £ or 12 to the shilling and 20s to the £.

Life was much simpler(?) back then. All changed in Feb 1971

https://www.bbc.co.uk/articles/c7224g3gjm6o#:~:text=On%2015%20February%201971%20%2D%20Decimal,to%20the%20current%20decimal%20system.