68°F to 75°F (20-24 degrees C).
A 1.0 TOG sleep sack is suitable for use in moderate temperatures, generally during the spring or autumn seasons. It is designed to provide a bit of insulation and warmth while still maintaining breathability.
1.0 TOG Sleep Sack is warmer than 0.5 TOG. The High TOG fabric will be warmer. You can choose 2.5 TOG or even 3.5 TOG if the tempura is lower.
But be careful, you don't want your baby overheated.
Since a 1.0 TOG sleep sack is designed for warmer temperatures, you'll want to dress your baby lightly underneath. Focus on breathable fabrics like cotton or bamboo in short sleeves and pants or a onesie.