To calculate from Celsius to Fahrenheit, you can use the formula:

°F = (°C × 9/5) + 32

So:

20°C = (20 × 9/5) + 32 = 68°F

30°C = (30 × 9/5) + 32 = 86°F

Therefore, 20°C is 68°F and 30°C is 86°F.