When to Go: A Food Traveller's Calendar

Two calendars decide a food trip and they almost never agree. One is the weather: whether you can stand outside for three hours without hating it. The other is the harvest: whether the thing you came to eat is actually being picked. Rome in August is 31 degrees and the artichokes finished in May. Mexico City serves chile en nogada from July to September, which is precisely when it rains every afternoon.

What follows is both calendars for all sixteen cities on this site, and a third one that catches more people out than either: when everything closes.

Best months here means the months we would choose for eating on foot, not the months with the most visitors. Where the two disagree we have gone with the food and the walking.

Most food seasons are approximate. A few are written into statute, and those are the ones you can plan a trip around, because a restaurant cannot serve what nobody is allowed to pick.

Italy's truffle law is the clearest case. A national act fixes a collection window for each species, and the prized white truffle runs from 1 October to 31 December. What almost nobody knows is that regions may vary it, and Tuscany opens on 10 September, three weeks ahead of the rest of the country. Then comes the part that makes the calendar visible to a visitor rather than only to a forager: selling fresh truffle outside the collection period is prohibited. If a Florentine restaurant is shaving fresh white truffle in July, something is wrong with the story.

The rest of the harvest calendar is biology, and it is just as reliable. In the Basque country the txotx season opens in mid-January with a shout and closes between late April and early May: for those four months the cider houses serve a fixed menu straight from the barrel, and for the other eight they largely do not. Portugal's sardine is a question of fat rather than fishing: the fish builds it from late spring through to about October, which is why the grill season and the fishery season match.

Thailand's durian has two seasons and not one, which trips up half the travel writing on the subject. The eastern crop runs April to June and peaks in May; the southern one runs June to August, and one southern province alone takes seventy per cent of its harvest in August. Vietnam's lychee is a June affair. Colombia's coffee, in the Antioquia that Medellin sits in, has its main picking from September to December, with a smaller mitaca in April and May, and the mechanism behind it is worth knowing: the trees flower in the dry spells and the fruit ripens about eight months later.

This is the one that ruins trips, because it is invisible until you are standing in front of a closed shutter.

Two of those deserve a note. Tet is bigger than the law says. Vietnamese labour law gives five days, the calendar stretches it to seven or nine with the weekend, and in practice the long-established places in Hanoi shut from a few days before and reopen anywhere between the fourth and the tenth day of the new year. That is six to fourteen days without the food you came for, and the markets are only properly back by about the sixth day.

And Ramadan cannot be diarised far ahead. It moves back roughly eleven days each year and takes about thirty-three years to work all the way round the seasons, and in Morocco the start is announced by the ministry on the evening of the sighting itself. Non-Muslim visitors are not affected by the rule against eating publicly, which applies to those known to be Muslim, but every restaurant hour in the medina changes and the evening becomes extraordinary.

Italy closes in August by law. It does not. A 2006 liberalisation act removed the obligation for bars and restaurants to close on Sundays, holidays and the half day midweek. August is custom, and a powerful one, but nothing compels it and plenty of places stay open.

Tsukiji closed in 2018. The wholesale market moved to Toyosu. The Outer Market is still there and still open, running on trade hours in the early morning and normal retail from about nine.

Matsutake is the great Japanese autumn mushroom. It is the great Japanese autumn import: domestic production has collapsed to a tiny fraction of what arrives from abroad. The season is real, the provenance usually is not.

Oysters only in months with an R. The rule is about refrigeration, and the American authority that used to promote it now writes it in the past tense. Farmed oysters are sold year round. There is a genuine seasonal risk from warm-water bacteria, but the variable is who is eating rather than which month it is.

Mexico City's rainy season is May to October. The national water commission puts it at June to September, and the millimetres agree: May and October both sit under 55 mm against 110 to 124 at the peak. Those two shoulder months are among the best in the year to be walking around eating tacos.

Thirteen of the sixteen cities here have an official 1991-2020 climate normal, filed by the national weather service with the World Meteorological Organization. Three do not, and we would rather say so than fill the gap from a commercial weather site.

Athens is the worst case: the station behind the long series closed in 2010, Greece is absent from the international archive, and the only current city normal is coastal and unusable for rainfall. Naples has temperature but no published monthly rainfall for the current thirty years. Lima has no official normal at all, which we checked from two directions, and this explains a widespread error: aggregator sites give Lima around 200 mm of rain a year by using a station 21 kilometres inland and higher up. The real figure for the city is closer to 13.

One number we did find is worth carrying into an August afternoon in Rome. The urban station in the centre averages a daily maximum of 22.5 degrees across the year, against 21.0 at Ciampino and 20.9 at Fiumicino. That 1.6 degree gap is the heat island, and it means the official summer figures understate what a walking tour in Testaccio actually feels like.