Most common cause for such a pain is Piriformis syndrome which is due to the muscle pressing on sciatic nerve. However there could be many other reasons for such pain which can only be evaluated after a thorough clinical examination. Cold climates does aggravate such symptoms like sciatica.
Next Steps
You can get an online consultation with me .
Health Tips
Avoid using wallet in the back pocket if you're doing so, hot fomentation and OTC NSAIDS for pain relief, piriformis stretch exercises.