The temperature dressing chart: what to wear at every degree
'What do I wear today' is really 'what do I wear at 7am that still works at 3pm'. Here is the full chart, calibrated for a dry adult walking between transport and buildings, plus the logic to adapt it.
75F and above
Linen or lightweight cotton, loose fit, light colors. One layer only - the mistake is adding a 'just in case' layer you then carry all day. If AC is your reality, a shirt over a tee beats a sweater.
65-75F: the easy zone
Long sleeves or short with a light overshirt. Jeans, chinos, midi skirts all work. This is the temperature where outfit formulas matter more than fabric science.
55-65F: the hardest band
Most people overdress here. The correct answer is one light-to-mid layer (denim jacket, chore coat, trench) over a single base. The key is choosing a layer you can comfortably keep on indoors, because you will not want to carry it.
45-55F
Two layers: knit plus jacket. This is sweater weather proper. Wind matters more than the number - add wind resistance (the trench, a waxed jacket) when the forecast mentions gusts.
35-45F
Three layers: base, knit, coat. Wool starts earning its keep. Hands and neck lose heat fastest - a scarf is worth 5 degrees of perceived warmth.
25-35F
Real coat weather: insulated or heavy wool, layers underneath, and footwear with actual soles (leather soles are ice skates). Thermal base layers replace bulk.
Below 25F
Extremities first: insulated boots, real gloves, hat. The torso is easy; the fingers are the problem. Layers you can vent when you hit heated interiors prevent the sweat-then-freeze cycle.
The 30-degree swing rule
Spring and fall days regularly span 30 degrees. The answer is never the heavy single piece; it is three light layers you shed progressively. A tee, an overshirt, and a jacket covers 45-75F gracefully.