Aurora tours are the one Lapland product where the rating tells you less than you think. A tour can be run well and still show you nothing, because the sky does not take bookings.
Not explicitly stated on page (typically evening tour) · Rovaniemi
Live price on the listing shown for your date, group size and currency at booking
5-8 hours · Rovaniemi
Live price on the listing shown for your date, group size and currency at booking
Not explicitly stated (approx. 2 hours outdoors) · Rovaniemi
Live price on the listing shown for your date, group size and currency at booking
Not explicitly stated · Levi
Live price on the listing shown for your date, group size and currency at booking
3 hours · Levi
Live price on the listing shown for your date, group size and currency at booking
The season runs from late August to early April in Finnish Lapland, per Visit Finland and the Santa Claus Village information service. The Finnish Meteorological Institute puts the likeliest window around midnight, give or take a couple of hours. That is why almost every tour below leaves in the evening and returns late; a 7pm start that is home by 9pm is selling you a bus ride.
Look down the list and you will see aurora tours rated 4.0 and 4.1 sitting beside husky and snowmobile products at 4.6 and 4.7. That gap is not a quality gap. It is people rating the weather. A tour with 1,588 reviews at 4.0 has taken far more travellers out than a 4.9 with 348, and a chunk of those one-star reviews say some version of "we saw nothing", which the guide could not have changed.
Read it this way instead: the review count tells you how established the operator is, and the written reviews tell you whether the guide worked for it, drove to clearer skies, and got people warm. That is the part a tour controls.
Some listings offer a money-back or free-repeat promise if nothing appears. That is a real commercial guarantee from that operator and it is stated on the listing. It is not a guarantee that you will see the aurora, and any site telling you otherwise is selling something.