Early autumn is the pick. If you can choose freely, come at the end of the warm half of the year. Daylight is still long enough for an operator to hold several slots a day, the crowds that fill a single manifest in high summer have thinned, and the air over the Bernese Alps tends towards the kind of clarity that makes the view from 4,000 metres worth the fare. The listing promises dramatic views across the Swiss Alps from the aircraft, and this is the stretch that delivers them most reliably alongside a manifest you can still get onto at short notice.
High summer is the fullest and the busiest. The longest daylight of the year means the most slots and the greatest flexibility if your morning has to move — a genuine advantage, and the reason many people come now. The trade is competition for those slots. One jump, one operator, one bus to Reichenbach with seats for jumpers only. Book the date before you travel, take the earliest slot you can, and keep the rest of that day loose: the booking runs 3.5 hours door to door and any waiting sits inside it.
Spring is the quietly good one. Daylight climbs week by week, the timetable opens up with it, and the manifest is not yet full. It is the stretch where you can decide on Tuesday to jump on Thursday and expect that to work. Snow stays high on the peaks for a good part of it, which is exactly the view people picture when they imagine skydiving over the Swiss Alps.
Winter is the quietest, and it asks the most of your schedule. Nothing about the jump changes: the same climb to 4,000 metres, the same 45 seconds at 200 km/h (120 mph), the same 5 to 7 minutes of canopy, the same tandem master and the same equipment from the operator. What changes is the number of hours available to fit you into. If you are jumping in the short-daylight months, give yourself more than one possible morning, book early in the stay, and read the cancellation line before you pay. People who plan it that way jump in winter perfectly happily, and they do it with the quietest airfield of the year.
Late autumn is winter with less snow on the peaks. Daylight is falling away and the timetable thins accordingly. Treat November the way you would treat January: spare mornings, early booking, no last-day plans.
Where the tandem flights sit in all this. The nine paragliding listings on this site fly through the year, and they are not season-bound in the way one climbing aircraft is. A wing launches from a mountain slope, not from 4,000 metres, which puts it in a wider band of usable conditions, and pilots choose a launch to suit the day — the FLYMATTERHORN VIP listing in Zermatt states that the takeoff location is selected according to the best conditions. The operators dress people for the cold, too: the Zermatt flight names a flysuit to keep you warm along with a helmet, hat and gloves, and the Mürren flight names boots or a jacket when necessary. If you are in Interlaken in a short-daylight month and want to be sure of getting into the air, $222 over the town between Lake Thun and Lake Brienz is rated 4.9 from 2,580 reviews and $209 over the Lauterbrunnen cliffs and waterfalls is rated 5.0 from 367.