Temperature spikes

I’ve recently started seeing temperature spikes (+ & -) in my graph which are also effecting my daily high/low readings. It seems to happen randomly. It will be fine for many days then I will suddenly get a day where there are several positive and negative spikes up to about 5 degrees from the actual temperature. This has only started happening in the last month. I’m not sure whether it’s my station or WD that’s causing this. My station is a Watson w-8681. Does anyone know what is causing this, and how it can be fixed?