I'm not sure if you were kidding or not, so I'll respond.
No, Average is not Average.
- Let's take a portfolio of 3 investments.
- Let's invest $100 into each investment.
If the 3 investments earn 1%, 2% and 3%, respectively, then the average return of each investment is SUM(1,2,3)/3 = 2% or $6.
However, the weighted average return of the same portfolio if the original investment of $300 was split up differently could be higher or lower.
For example, invest $50 in the 1% investment, $100 in the 2% investment and $150 in the 3% investment. In that situation, you would gain 2.33%, or $7, on the same $300 starting amount.
Therefore, the average temperature over a given time period might not be the same as the weighted average temperature over that same time preiod.
Unfortunately, I don't think there is enough data given in the OP to determine anything except the average temp.