It is doubtful that aurorae would directly cause EMI interference in coils as their output is in the visible EMF spectrum.
That said, aurorae are the effects of ionised particulate solar wind bursts on our atmosphere and there are other effects that are less understood. A recent example was the STEVE event photographed over South Australia last weekend.
https://live-production.wcms.abc-cd...ropW=720&xPos=0&yPos=200&width=862&height=485
Apart from elevated levels of ionised particles during solar maximums, the sun also emits higher levels of radiation bursts in the EMF spectrum that can be registered by detector coils. This is just one many noises that we refer to as EMI in our detectors. The other main ones being man-made or weather (lightning) activity.
It is unclear whether the solar maximums cause hotter conditions as these maximums involve increased sunspot activity which actually dims the EMF radiance from the sun's surface part of which we feel as heat. This correlates with other studies eg evaporation rates in salt production enterprises.
The main driver as to why we have such stinking hot summers in Australia is that the Earth's distance from the sun varies from 152 to 147 million km due to the eccentricity of the Earth's orbit. Unfortunately for us the closest approach occurs on 26th January in the middle of our summer which involves an increase in solar radiance to about 7% (don't ask me how that is calculated) over the radiance during the winter months.
Don't worry too much because in about 13,000 years the tilt of the Earth's axis will wobble (precess) so that our summer will coincide with our maximum distance away from the sun so our summers should be a bit cooler.
For the present though, we will be stuck with our very hot summers and I for one will tend to avoid doing too much detecting during those times and concentrate more on my warm night-time astronomy endeavours and perhaps photographing some nice aurorae.