Many meteorologists agree that there is little accuracy in weather forecasts that extend beyond seven days, so 30-day weather forecasts are not considered accurate. Oftentimes, a forecast extending beyond seven days is no more accurate than historical averages.
The inaccurate predictions that arise from attempting to predict the weather beyond seven days can negatively impact the view of the science of meteorology and undermine the credibility of a rigorous scientific practice. However, meteorological models are exceedingly accurate when predicting the weather on a shorter time frame. The science of climatology has consistently proven that it is more effective at predicting temperature over longer time frames than meteorological forecasts.