The two shoulder seasons solve the same problem, cheaper and quieter than summer, and families still end up stuck between them. The reason is rarely the weather photo. It is that spring sits next to fixed school dates and fall sits next to storm season, and those two constraints pull in opposite directions depending on who is traveling.
I run the comparison the same way every time: months first, then money, then the specific family. Here is what the evidence actually shows.
What differs between the two windows
Spring shoulder season runs roughly March to early June, fall roughly September to mid-November, and the overlap in temperature is larger than people expect. A week in Lisbon in April and a week in Lisbon in October both land near 19 or 20 degrees Celsius during the day, and both ask for a light jacket at night.
The differences sit elsewhere. Spring brings longer daylight by the end of the window and reliable wildflowers; fall brings warm sea temperatures left over from summer, which matters the moment children want to swim. Spring also arrives with rain in short bursts, while fall rain tends to come in longer, greyer stretches, particularly on the Atlantic coast.
Month by month for families
March is the cheapest of the two by a clear margin, and the coldest, with sea temperatures that stop most children at the water's edge. April is the strongest spring month for city trips: 15 to 19 degrees across southern Europe, gardens at their best, and queues still half the summer length.
- March: lowest rates of the year, longest evenings of the two seasons, water too cold for most children.
- April: the balanced month for cities and gardens, rain in short bursts rather than long grey stretches.
- May: reliable weather, but the long weekend clusters push rates up in the second half.
- September: sea still near summer warmth, a late-summer premium of 25 to 35 percent over October.
- October: the strongest fall month for walking and city trips, with crowds thinning from the second week.
May is where spring stops being a bargain in places that school calendars have discovered, because several countries take their long weekend clusters in the same fortnight. On the fall side, September is the sweet spot for beach weeks, October is the strongest month for city and walking trips, and November is genuinely off-season south of Rome, with shorter opening hours at attractions to show for it.
Prices, crowds and booking risk
The price order is consistent across most of our test routes: March cheapest, then October, then April, then May, then September, with September carrying a late-summer premium of roughly 25 to 35 percent over October on the same room.
Crowds behave differently than prices. Spring crowds are day-trip crowds concentrated around Easter and the late April weekends, so a midweek arrival absorbs them easily. Fall crowds thin steadily from the second week of October onward, which is why a fall trip rewards a later start rather than an earlier one.
The risk sits asymmetrically. Spring risk is calendar risk, since a three-week move can break the school dates entirely. Fall risk is weather risk in the Atlantic and Caribbean basin, where the official hurricane season runs to the end of November, and where a trip needs insurance rather than optimism.
One practical note on that asymmetry: the properties price spring risk into their cancellation terms, while fall risk shows up in the rates. April rooms frequently carry free cancellation into the final fortnight, and September rooms at the same hotel often do not, which is exactly the wrong way round for a family that needs flexibility on both ends.
Where each window wins
Spring wins for families with the youngest travelers: strollers, museum-heavy city trips, gardens, and any itinerary built around walking distances under three kilometers a day. It also wins whenever the trip is expensive anyway, because March and April rates on the same properties run 20 to 30 percent under their September equivalents.
Fall wins for families who want water: sea temperature still near summer levels through September and early October, outdoor pools open, and evening dinners at a comfortable hour. It also wins for school-age children with rigid calendars, because the October half-term window exists whether we plan for it or not, and fighting it costs more than accepting it.
How I decide for a specific family
I ask three questions and let the answers settle it. Can the dates move, or are they nailed to a school term. Does the trip depend on swimming. Is the budget tight enough that a 30 percent swing changes the destination.
Movable dates plus a tight budget points at March or April. Fixed dates plus swimming points at late September. When both families I compared last season answered yes to swimming and no to movable dates, one took Crete in October and the other took the Algarve in April with a heated pool as the compromise, and both trips came in under the number they started with.
Start with your calendar rather than with the forecast: check which fall half-term or spring break dates your school actually publishes this year, then price the destination inside those dates. The weather is similar enough between the two seasons that the calendar should be deciding this one.