Season of the year calculator
Enter a date and a hemisphere to get its meteorological season: 15 July 2026 is summer in the north, while in the south July belongs to winter. Seasons are fixed three-month blocks, the way weather services count them. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Date
- 2026-07-15
- Hemisphere
- northern
- Year
- 2,026
- Month
- 7
- Day
- 15
- Month name
- July
A season of the year calculator answers a practical question that depends on both the calendar and where you stand on Earth: given a date, which meteorological season is it in this hemisphere? Paste an ISO date in year-month-day form, choose northern or southern, and the tool returns the season key (winter, spring, summer, or autumn), a readable label, the three months that belong to that season under the meteorological convention, and step-by-step classification. Meteorological seasons are fixed three-month blocks used by weather services and climate summaries—not the moving astronomical solstices and equinoxes—so June is always northern summer and December is always southern summer.
Meteorological seasons and why the hemisphere matters
Meteorological seasons divide the year into four fixed three-month blocks that align with monthly climate statistics rather than the exact moments of solstices and equinoxes. In the northern hemisphere the blocks are winter in December, January, and February; spring in March, April, and May; summer in June, July, and August; and autumn in September, October, and November. In the southern hemisphere those same calendar months flip: December through February is summer, March through May is autumn, June through August is winter, and September through November is spring.
That inversion is not a styling choice—it reflects the fact that Earth’s tilt puts opposite hemispheres into opposite solar seasons at the same time. A calculator that assumes northern seasons by default would mislabel every mid-year winter festival in Chile or Australia and every December summer holiday in New Zealand. This tool therefore requires an explicit hemisphere string and refuses values that are neither northern nor southern, so callers cannot accidentally publish “summer” for a southern winter date.
The season keys are stable English machine labels: winter, spring, summer, and autumn. Autumn is used instead of fall because it is the term preferred in international meteorology and in many non-US English locales, while the landing prose still helps people who search for fall.
Because classification depends only on the month number and the hemisphere flag—not on the day of the month within a valid date—the fifteenth of July and the first of July share the same meteorological season once the hemisphere is fixed, which matches how monthly climate normals are published.
Practical tips, limits, and related searches
Always send a full calendar date, not a datetime with a time component or a trailing Z; this tool deliberately refuses extended ISO timestamps so callers cannot encode timezone-dependent midnights that would change the calendar day. When teaching or testing, keep a small known set: a northern midsummer date such as mid-July, the same calendar day with southern hemisphere to show winter, a December northern winter versus southern summer pair, and a deliberate failure with hemisphere set to something other than northern or southern.
Round-trip checks are easy: look up the month number, apply the three-month meteorological table for that hemisphere, and confirm that the published season key matches. Year bounds stop at nine thousand nine hundred ninety-nine to keep four-digit ISO strings well defined for this product surface. This landing targets people searching for a season of the year calculator, meteorological season by date, or northern versus southern hemisphere seasons online; it is not an astronomical solstice calculator, not a day-of-week tool, and not a business-day or age calculator.
Prefer this capability when you already have one ISO date and a hemisphere and only need the climate-style season; if you need the weekday name, use a day-of-the-week calculator instead.
What you can do with it
Travel and event copy by hemisphere
Marketing teams label campaigns as summer or winter using the destination hemisphere so December offers say summer for Sydney and winter for New York.
Scheduling and UI localization checks
Product teams verify that seasonal themes and icons flip correctly when the same ISO date is viewed under northern versus southern settings.
FAQ
What are meteorological seasons?
They are fixed three-month blocks used by weather and climate services: in the north, winter is Dec–Feb, spring Mar–May, summer Jun–Aug, autumn Sep–Nov. The southern hemisphere uses the inverted mapping.
Why do I have to specify a hemisphere?
The same calendar month is opposite seasons on opposite sides of the equator. Without northern or southern, any single answer would be wrong for half the planet.
Is this the same as astronomical seasons?
No. Astronomical seasons start at solstices and equinoxes, which shift by day and year. This tool uses fixed meteorological months only.
Is the season calculator free?
The browser tool is free and runs locally.
Does the day of the month change the season?
No. Only the month and the hemisphere matter, so 1 July and 15 July are both summer in the north. Meteorological seasons are whole three-month blocks, which matches how monthly climate figures are published.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/date/season \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"date":"2026-07-15","hemisphere":"northern"}'const res = await fetch("https://api.kit.forhosting.com/date/season", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"date": "2026-07-15",
"hemisphere": "northern"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/date/season",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"date": "2026-07-15",
"hemisphere": "northern"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/date/season", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"date":"2026-07-15","hemisphere":"northern"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"date":"2026-07-15","hemisphere":"northern"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/date/season", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"date": "2026-07-15",
"hemisphere": "northern"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "date.season",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Limits
year_min | 1 |
year_max | 9999 |
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Invalid hemispheres (anything other than northern or southern) and impossible calendar dates are rejected with a clear invalid_input error instead of a silent wrong season.
How to call the API and what comes back
The hemisphere field may also be supplied as hemi or region; after trimming and lowercasing it must resolve to northern or southern. Send a JSON body with two required string fields: date and hemisphere. The date field may also be supplied under the aliases iso_date, value, or day, and must match the exact pattern of four digits, hyphen, two digits, hyphen, two digits, representing a real Gregorian day in the inclusive year range from one through nine thousand nine hundred ninety-nine. Short aliases north, south, n, s, nh, and sh are accepted for convenience in forms and scripts, but arbitrary strings such as east, equator, or both are rejected with invalid_input. On success the response echoes the canonical date string, year, month, day, and English month_name; sets hemisphere to the normalized northern or southern value; sets convention to the string meteorological; sets season to the lowercase key and season_label to the title-cased display form; sets season_months to the three month numbers that define that season in the chosen hemisphere; and includes a short message plus an ordered steps array that restates the parse, the hemisphere choice, and the table lookup. Failed validation—missing fields, non-string types, bad date shape, out-of-range year, impossible month or day, a non-leap twenty-ninth of February, or a hemisphere that is neither northern nor southern—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item and zero marginal unit price.
Practical tips, limits, and related searches
Prefer the primary field names date and hemisphere when you control the client; aliases exist for compatibility with forms that label controls iso_date or region. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately send bad hemispheres or impossible dates.
Integration use cases
Climate and education fixtures
Teachers and climate apps generate deterministic meteorological season labels for worksheets and quizzes without relying on the host clock.
Technical questions
What values are accepted for hemisphere?
northern and southern (case-insensitive). Short aliases north, south, n, s, nh, and sh are accepted. Anything else returns invalid_input.