Edinburgh in May is Scottish late spring — 14°C / 57°F afternoons, 6°C / 43°F mornings, 10 rain days, the Royal Mile cobble at peak walking weather.
Edinburgh in May is Scottish late spring. UK Met Office data put afternoon highs at 14°C / 57°F and overnight lows at 6°C / 43°F with 10 rain days. The Edinburgh climate runs cooler and wetter than London — the North Sea wind and Forth estuary cool evenings 4-6°C / 7-11°F below midday. The dressing register is Scottish heritage: Harris Tweed (Outer Hebrides handwoven wool since 1846, Orb-mark certified — the most-cited Scottish heritage textile, made on Lewis, Harris, Uist, Barra islands); Pringle of Scotland (Hawick-founded 1815, the heritage Scottish cashmere — the Argyle pattern is Pringle's invention); Mackintosh (Glasgow-founded 1823, the heritage rubberized waterproof coat — the original raincoat); Burberry-equivalent local Holland Esquire (Edinburgh tailoring); Walker Slater (Edinburgh-founded tweed tailoring, Princes Street flagship); Johnstons of Elgin (Scottish cashmere since 1797). The Royal Mile (the heritage 1-mile stretch from Edinburgh Castle to Holyroodhouse Palace) is cobble; structured leather boots only. Old Town and New Town hold the heritage. Stockbridge is creative-residential. Leith is the dockside-creative.
Edinburgh May is Scottish late spring — Edinburgh Castle clouds breaking by mid-morning, the Royal Mile cobble at peak walking weather, the Pringle of Scotland Princes Street flagship putting the spring cashmere collection in the window. Harris Tweed and Mackintosh outerwear hold firm.

The Edinburgh May daily anchor against UK Met Office 6°C / 43°F mornings climbing to 14°C / 57°F by afternoon. Pringle of Scotland (Hawick 1815) invented the Argyle pattern; the Princes Street flagship runs spring cashmere through May. Belinda Robertson (Edinburgh 1992) and Begg & Co (Ayr 1866) are local alternatives at the same register.

Layers under the wool sweater for the 8°C / 14°F daily swing the UK Met Office records at the Edinburgh Royal Botanic Garden station. Sage or oat merino sits cleanly under the Pringle cashmere; strips down for the Stockbridge Sunday market or a Royal Mile walk by 1pm without overheating.

Edinburgh May runs 10 rain days plus the Haar (North Sea fog rolling through Old Town mornings). Mackintosh (Glasgow 1823) is the original rubberized raincoat — the Princes Street store carries the heritage trench. Pack the bonded-cotton version for daily wear; the rubberized cape for serious downpour.

Harris Tweed (Outer Hebrides since 1846, Orb-stamp protected by Act of Parliament 1993) in heather grey or bottle green handles the 4-6°C / 7-11°F North Sea wind that drops Edinburgh evenings well below midday. Walker Slater on Victoria Street tailors the heritage trouser locally.

The Royal Mile is medieval cobble end to end; Calton Hill is volcanic gravel; Dean Village paths are uneven stone. Loake or Joseph Cheaney leather boots in oxblood or chestnut survive both. Skip ballet flats — the Castle Esplanade gradient defeats them.

Edinburgh May mornings still drop to 6°C / 43°F per UK Met Office — a wool overcoat or Harris Tweed jacket from Walker Slater (Edinburgh 1989) carries the morning Royal Botanic Garden walk. The Anta (Aberdeen 1984) tartan-lined jackets layer under for cooler days.

The Kitchin (Leith, 1-Michelin since 2007), Restaurant Martin Wishart (Leith, 1-Michelin since 2001), and Number One at the Balmoral all run smart-casual. A cream cotton or oat wool button-down tucks under the Harris Tweed jacket for the 19:30 booking; works for cocktails at Bramble after.

Strathberry (Edinburgh 2013, the leather house Meghan Markle made famous) crossbody in tan or oxblood works hands-free across the Royal Mile cobble. The Johnstons of Elgin (Moray 1797) cashmere scarf in heather or sage handles the harbor-wind drop at Leith Shore by 8pm.
Wool blend base · trousers · boots · wool sweater · Mackintosh · scarf · crossbody. Coffee at Cult Espresso 8am, Edinburgh Castle 9am, Royal Mile walk 11am, lunch at The Witchery by the Castle 13:00.
Trousers · button-down · Harris Tweed jacket · structured boots. Dinner at The Kitchin (Leith, Michelin-star) or Number One (Balmoral) 19:30; cocktails at Bramble after.
A suggested look — Edinburgh May morning look: sage merino base, heather oatmeal cashmere sweater, Harris Tweed trousers, oxblood boots, bottle green Harris Tweed jacket.
Per the UK Met Office: average daily high 14°C (57°F), low 6°C (43°F), 10 rain days totalling 50mm. Scottish late spring. Daylight 16h 15m. UV index 4-5 (moderate). The North Sea wind cools harbor evenings 4-6°C / 7-11°F below midday. Edinburgh runs cooler and wetter than London by 2-4°C / 4-7°F.
Harris Tweed is the Outer Hebrides (Scotland) handwoven wool fabric — protected by the Harris Tweed Act 1993 (the only fabric in the UK with its own act of Parliament). Made only on Lewis, Harris, Uist, Barra islands, hand-woven on hand-looms in weavers' homes, from 100% Scottish wool dyed and spun in the Outer Hebrides. The Orb mark certifies authenticity. Pringle of Scotland (1815) and Walker Slater (Edinburgh) make Harris Tweed jackets, trousers, accessories. Pack: a Harris Tweed jacket handles 8-15°C / 46-59°F mornings well.
Pringle of Scotland (Hawick-founded 1815, the heritage Scottish cashmere — Princes Street flagship); Mackintosh (Glasgow-founded 1823, the heritage rubberized waterproof coat); Johnstons of Elgin (Scottish cashmere since 1797 — the heritage Scottish-cashmere house); Walker Slater (Edinburgh tweed tailoring, Princes Street flagship); Holland Esquire (Edinburgh tailoring, Burberry-equivalent local); Anta Scotland (Banchory, Scottish-tartan homeware); Hewitson (Edinburgh leather goods); Tartan Weaving Mill (Royal Mile, traditional Scottish tartans); Edinburgh Woollen Mill (multiple, mid-tier Scottish woolens). The Princes Street, George Street, and Royal Mile hold the highest concentration.
Yes — Arthur's Seat (the 251m / 823ft volcanic hill in Holyrood Park, the most-photographed Edinburgh hike) is at peak walking weather in May. The 5km / 3-mile loop is moderate; allow 2-3 hours. The trail is rocky-and-grassy, sometimes muddy after rain. Pack: layered cotton/wool blend, mid-weight wool sweater, Mackintosh raincoat, structured leather boots (skip leather sneakers — uneven volcanic terrain), scarf, sun hat, polarized sunglasses. The view from the summit takes in the Old Town, New Town, Forth estuary, and the Pentland Hills. Skip on heavy-rain days; the path can flood.
Edinburgh Castle (the most-visited Scottish attraction, the volcanic-rock fortress); Royal Mile (the heritage 1-mile stretch from Castle to Holyroodhouse Palace, with the Cathedral of St Giles); Holyroodhouse Palace (the official Scottish royal residence); National Museum of Scotland (the most-cited Scottish museum); Scottish National Gallery (Princes Street, free entry); Calton Hill (volcanic-monument cluster including the Nelson Monument and the National Monument of Scotland); Stockbridge (creative-residential, the Sunday market); Leith (dockside, with The Kitchin Michelin-star); Princes Street Gardens (between Old Town and New Town). Pack: layered cotton/wool, mid-weight sweater, Mackintosh, structured boots, scarf.