TravelCityIndex
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TravelCityIndex

One page of sourced numbers per city: what a day costs, what the travel advisory says, and which months score best on the weather.

Data: GeoNames, Open-Meteo, World Bank, US State Department, UK FCDO.

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© 2026 Travel City Index. Every number on this site comes from a dataset named on the page that shows it.
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How this works

Methodology

Every figure on this site is computed from a public dataset with the formulas below. They are published here so any number on any page can be checked.

Daily cost

A daily cost is an estimate, not a quoted price. It starts from a US baseline for each travel style, is converted to the destination's price level using the World Bank's purchasing-power conversion factor, and is adjusted for how large and how central the city is.

tier_usd = round(baseline × price_level × size_factor / 5) × 5

US baseline per day

Travel styleBaseline
Budget$90
Mid-range$210
Luxury$450

Size factor

City populationFactor
5,000,000 or more1.25
1,000,000 or more1.10
300,000 or more1.00
under 300,0000.90

A national capital adds 0.05 to its factor (GeoNames feature code PPLC).

Worked example: Tokyo

Tokyo's country price level is 0.6487 and its size factor is 1.30 — 1.25 for a population of 5,000,000 or more, plus 0.05 because it is the capital. That gives:

  • Budget: 90 × 0.6487 × 1.30 = $75 a day
  • Mid-range: 210 × 0.6487 × 1.30 = $175 a day
  • Luxury: 450 × 0.6487 × 1.30 = $380 a day

Local-currency amounts are the USD figure times the World Bank exchange rate, rounded to two significant figures — a reading, not a conversion to spend against.

Visit score

Every city gets one score out of 10 for each of the twelve months, from the Open-Meteo climate record: how comfortable the temperature is, how wet the month is, and how much sun it gets.

visit_score = 0.5 × temp + 0.3 × rain + 0.2 × sun

Temperature (0.5 of the score)

Scored on the mean of the month's average high and low. A mean outside every band below scores 0.

Daily meanScore
8 to under 14 °C3
14 to under 18 °C7
18 to 26 °C10
over 26 to 29 °C7
over 29 to 33 °C3
Anything colder or hotter0

Rainfall (0.3 of the score)

Monthly precipitationScore
under 40 mm10
under 80 mm7
under 150 mm4
150 mm or more1

Sunshine (0.2 of the score)

Average daily sunshine hours × 1.2, capped at 10 — so 8.33 hours a day or more scores full marks.

Best, peak and off season

  • Best months: the months scoring 7 or higher, at most 4 of them, highest first. If fewer than 2 months clear that bar, the top 3 of the year are used instead, so no city is left without a recommendation.
  • Peak season: the best months, plus July and August whenever they score 5 or higher — the northern-hemisphere holiday bump, even outside the best window.
  • Off season: the 3 lowest-scoring months.

All three are listed in calendar order, because they are a reading of the year rather than a leaderboard.

Safety

Safety on this site is not a score we invented. It is the US State Department's travel advisory level for the city's country, in the department's own wording, alongside the UK Foreign, Commonwealth & Development Office's safety and security text for the same country.

LevelState Department wording
1Level 1 – Exercise normal precautions
2Level 2 – Exercise increased caution
3Level 3 – Reconsider travel
4Level 4 – Do not travel
  • Advisories are issued per country, so every city in the same country shares one level. A city page never claims a city is safer than its country's rating.
  • When no advisory can be matched to a country, the page says so rather than assuming the lowest level.
  • The United States is shown as not rated: its own State Department does not issue an advisory for it.

What the AI does

The intro paragraph, the FAQ answers, the sample price list and the short notes on cost, safety and timing are written by a language model. Its job is interpretation: turning a table of figures into a couple of readable paragraphs.

It is not allowed to supply a number. Every figure it may use is handed to it from the datasets, and the draft is checked before publication: a money amount that does not match a cost tier, a seven-day total or a listed sample price fails the check, as does a safety note that goes beyond what the FCDO text says or omits the advisory level. A page that fails twice is not published.

Nothing on this site recommends a named hotel, restaurant or tour, and nothing is paid placement. The full source list names every dataset and its licence.

How often this updates

  • GeoNames city database — Fetched once when a city enters the index; re-fetched by hand.
  • Open-Meteo climate archive — Refreshed yearly, which moves the three-year window on by one year. A three-year average does not change week to week.
  • World Bank price level and exchange rate — Refreshed yearly, when the World Bank publishes the new indicator year.
  • IMF World Economic Outlook price level (Taiwan) — Refreshed by hand yearly, alongside the World Bank refresh.
  • US State Department travel advisories — Refreshed every Monday.
  • UK FCDO foreign travel advice — Refreshed every Monday.

The written interpretation is regenerated when the data behind it changes, not on a schedule of its own. Every page carries the date each of its datasets was fetched, so a figure can always be placed in time.

Corrections

If a number here looks wrong, it is worth telling us — the formula, the input or the page could each be at fault, and all three are ours to fix. Report it with the page URL, or read the source list first.