Before revision:  A model with time-varying speed of mean reversion, seasonal mean,  local volatility that depends on the average temperature and time for the contract period is proposed. Based on this model , pricing models for futures, options on futures, and basket futures for cumulative average temperature and growing degree-days are presented.
After revision:  A model with time-varying speed of mean reversion, seasonal mean, local volatility that depended on the local average temperature was then proposed. The model was extended to a multi-dimensional model for different but correlated locations. Based on these average temperature models , pricing models for futures, options on futures, and basket futures for cumulative average temperature and growing degree-days are presented.