Sri Lanka in November & December: How to Pick Dates Around the Second Inter-Monsoon and Northeast Monsoon

Search for Sri Lanka's weather and the first question that comes up is "when is the dry season?" The island doesn't have one dry season that applies everywhere at once. The Department of Meteorology divides the year into four rainfall seasons, and in the same month the weather on one side of the island can be the opposite of the other.

November and December are the trickiest pair. They sit in two different seasons, and the boundary between them shifts by days or weeks from one year to the next. If you have to book non-refundable hotels and tours in advance, that moving boundary turns into a money problem.

This guide doesn't try to predict the weather. It's a checklist for choosing dates and placing bookings while assuming the boundary will move.

The four rainfall seasons the Met Department uses

Sri Lanka's Department of Meteorology groups the year into four periods by rainfall pattern. This is the frame to start from before you look at any month-by-month averages.

• First inter-monsoon — March to April · A transition period with light winds and frequent afternoon and evening thunderstorms
• Southwest monsoon — May to September · Rain concentrated on the western and southwestern slopes and the central hills; the north and east stay comparatively dry
• Second inter-monsoon — October to November · Transition again. Winds slacken and thundery showers spread across the whole island
• Northeast monsoon — December to February · Rain concentrated in the north and east, while the west and southwest coasts enter their driest stretch of the year

November falls in the second inter-monsoon; December falls in the northeast monsoon. So a November–December trip isn't a matter of picking dates inside one season — it's a decision about whether to cross the line where the seasons change.

What "second inter-monsoon" actually means for your days

Travel write-ups tend to label November as either the end of the rains or the start of the dry season. By the Met Department's own definition it's neither. The second inter-monsoon is a transition in which the monsoon winds haven't settled into one direction, and its signature weather is not all-day rain but thundery showers bunched into the afternoon and evening. When department officials describe this period, the phrase that keeps coming up is "evening thundershowers."

Translate that into an itinerary and the difference is stark.

• A dry-season itinerary stacks outdoor activity across the whole day and leaves travel for the evening. One shower and the rest of the day collapses.
• A shower-tolerant itinerary puts the outdoor centrepiece in the morning, attaches one indoor fallback to every afternoon block, and builds buffer into every transfer. Rain changes the order, not the day.

November itineraries don't fail because it rains. They fail because they were built on the assumption that it wouldn't. In identical weather, the two plans feel like different trips.

One more thing worth knowing: November and December are also when tropical cyclone activity in the Bay of Bengal picks up. Separately from everyday showers, an approaching system can disrupt flights, trains and boat tours for several days at a time. That's exactly why the official forecast routine below matters.

Deciding whether to push a west-coast trip to December–February

If your plan centres on the west and southwest coasts — Colombo, Bentota, Galle — then the northeast monsoon window of December to February (travel guides usually stretch it to March or April) is this coast's driest stretch. If you're weighing a November departure against a later one, these four questions usually settle it.

1. Is the ocean the point of the trip? If swimming, surfing, whale watching or boat tours make up more than half your days, waiting for December onwards is the better bet. Water activities are hit less by the rain itself than by swell and cancelled sailings.
2. Can you move the dates at all? If your leave is locked to November, "just go somewhere drier" is a narrower option than it sounds. While the west and southwest dry out from December to February, the north and east move into their northeast monsoon — so November isn't a month where one side of the island is reliably dry. In that case, change the shape of the itinerary rather than the region.
3. Is off-season pricing part of why you're going? November is the shoulder month right before high season. The savings on rooms and tours and the thinner crowds are real, and if your plan leans on ruins, tea country and city days — things you can shuffle indoors and out — November holds up well.
4. Is the booking non-refundable? Locking a non-refundable November beach stay means carrying all of the weather risk yourself. Going on the same dates with flexible terms changes the nature of that risk entirely.

The northeast monsoon doesn't start on a calendar date

This is the single most misread part of a November–December trip. The northeast monsoon doesn't begin on a fixed day. The Met Department watches pressure and wind patterns and announces it in stages — along the lines of the monsoon gradually establishing over the island — and the timing differs every year. Early December is typical, but some years run earlier and some later. A table that says "northeast monsoon: from 1 December" is describing the climatological average, not this year's announcement.

So if you're departing in late November or early December, go to the source rather than to secondhand summaries. In this order:

1. Check the Met Department's own site for the daily forecast, the weekly weather outlook and the 15-day forecast. Commentary about where the monsoon stands appears here first.
2. Look at the department's GIS weather portal for the regional rainfall picture. The distribution where you'll actually be matters more than an island-wide average.
3. Install the department's mobile app (Anawaki, Android) so you get location-based forecasts and warnings while you're there.
4. Cross-check with local news that quotes the department. Monsoon onset statements, heavy-rain advisories and cyclone warnings show up in Sri Lankan media right after they're issued.
5. Ask your hotel and tour operators directly. Road conditions, boat sailings and site access limits never make it into a forecast — this is the only place you'll get them.

Three things to confirm before you book anything non-refundable

What costs you money in November and December isn't the rain. It's whether you can change plans once the weather changes. Check these three before you pay.

1. The exact wording of the cancellation and change policy. How many days out does free cancellation end? Is bad weather listed as a valid refund reason? And if a refund isn't possible, can you move the date? In this season, date flexibility is often the more useful term of the two. Screenshot the policy page and keep it.
2. The rain policy. Ask before booking what happens if the weather turns. The answer is almost always one of four: run it the next day, switch to an indoor or alternate route, partial refund, or nothing at all. The tour you didn't ask ends up being the most expensive line in your budget. This matters most for anything where the go/no-go call is made that morning — boats, whale watching, balloon rides.
3. Your domestic transfers. Heavy rain hits the road to the place before it hits the place. Count how many mountain roads, train legs and boat connections your itinerary contains, and check whether each one has an alternative. Above all, avoid a long transfer the day before your international flight home.

Seasonal rainfall shares: a reference point, not a decision rule

It's tempting to pick dates off a figure like "November accounts for X% of annual rainfall." Those shares vary a lot by source.

A University of Colombo paper on the "burst" of the northeast monsoon cites long-term figures from Domroes (1974), putting the seasonal shares of annual rainfall at roughly 21% for the first inter-monsoon, 38% for the southwest monsoon, 16% for the second inter-monsoon and 25% for the northeast monsoon. Two caveats belong with those numbers.

• They are figures from a 1974 study as cited in that paper — not official numbers published by Sri Lanka's Department of Meteorology.
• More recent analysis lands somewhere quite different. A 2023 study of Sri Lanka's rainfall regimes in a hydrological sciences journal reports 30% for the southwest monsoon, 30% for the second inter-monsoon, 26% for the northeast monsoon and 14% for the first inter-monsoon. For the second inter-monsoon alone, that's 16% versus 30%.

The gap comes from different study periods, station networks and season definitions. The practical takeaway is simple: use the shares only to confirm that rain is part of the season in November, and make the date decision from this year's Met Department forecasts.

Leaving after mid-November? Re-check two weeks out

A departure after mid-November sits closest to the northeast monsoon boundary. Run this list once two weeks before you fly, then again two or three days out.

• Does the Met Department's weekly outlook mention the northeast monsoon — establishing, transitioning, increasing rainfall?
• Are there any advisories about a tropical system in the Bay of Bengal?
• Has a heavy-rain advisory or warning been issued for your regions in the last two weeks?
• When is the free-cancellation deadline on each booking? That date, not your flight date, is your real decision deadline.
• What's the operating status of the train and road legs in your plan, and have any changes been posted for flooding or landslides?
• Does your travel insurance cover weather disruption — specifically trip-change and cancellation costs?
• What are the change fees and conditions on your flights?

The point of this pass isn't to decide whether to cancel. It's to have the information in hand before the free-cancellation deadline passes. Anything that arrives after that date can't be acted on.

Packing and routing for a shower-tolerant trip

What to pack

• A light rain jacket or poncho — hands-free beats an umbrella around ruins and markets
• A dry pouch or zip bags for phone, passport and cash; showers start within minutes, with no warning
• Two or three quick-dry outfits — cotton stays damp all day in this season
• Sandals you don't mind soaking, plus trainers — one pair of shoes means starting the next day in wet ones
• A power bank — all the extra map, translation and forecast checking drains a phone fast
• A travel clothesline or folding hangers — you'll have more to dry than you expect

How to route the days

1. Put the outdoor centrepiece in the morning. Thundery showers cluster in the afternoon and evening.
2. Attach one indoor fallback to every afternoon block. Museums, temple interiors, tea factory tours, a massage, a café, a cooking class. Write them down by area in advance and you won't be searching in the rain.
3. Build buffer into transfers. Hill roads and trains run late often. Don't schedule a booked activity immediately after arriving on a travel day.
4. Change hotels less often. A day that stacks checkout, transfer and check-in is the worst one to get rained on. Two or three bases with day trips out and back suits this season better.
5. Front-load the weather-dependent activities. You can only retry something if there are spare days left behind it.

You need to be able to check the forecast on the spot

Every item above assumes you can check something immediately, wherever you are. Reading the day's regional forecast over breakfast and reordering the morning. Messaging a tour operator about today's sailing. Finding an alternative when the train is delayed. Searching for a nearby indoor option the moment it starts. None of that works well if it has to wait for hotel Wi-Fi.

Sri Lanka has broad 4G/LTE coverage in Colombo, the main towns and the tourist hubs. 5G has launched commercially on Dialog and SLT-Mobitel, but it's still concentrated in Colombo and other urban areas, so 4G is what you'll actually be riding on. Signal thins out on some stretches between the hill country and the inland sites, so it's worth downloading the day's forecast and offline maps before you set out.

Installing an eSIM before you fly means forecasts, ride-hailing and hotel messages work from the moment you land. On a shower-tolerant itinerary, the ten seconds it takes to see where the rain actually is can reorder your whole day.

Five days around Colombo and Galle or two weeks circling the island, the data you need in November and December amounts to opening a regional forecast each morning and sending one message to an operator.

Official sources to check yourself

The season boundaries are long-term averages. For how the monsoon is actually behaving this year, and for warnings, the Met Department is the only authority that counts. Check these before you fly and while you're there.

• Sri Lanka Department of Meteorology — daily, weekly and 15-day forecasts and warnings
• Met Department GIS weather portal — weather.meteo.gov.lk (regional rainfall distribution)
• Disaster Management Centre, Sri Lanka — flood and landslide situation reports