Before heading out to the course for a round it might be a good idea to go through a quick checklist:
1. Check the forecasted temperature for the entire duration of your round (approx. 4 hours). If warm and sunny, bring sunscreen and lots of water to stay hydrated. If cold, bring extra layers, toque and gloves.
2. Check weather radars for low pressure systems/likelihood of precipitation. If it is going to rain, decide if it is worth golfing in it (I typically do not mind light showers). Pack rainproof jacket/pants and rain gloves are great for dryness and grip.
3. Check wind speeds. If they are moderately high, it is probably not worth going. Personally, wind speeds above 40km/hr tend to be the cutoff point for me.
4. If there is lightning forecasted, stay off the course!