Comrades Marathon Weather Guide: Surviving 56 Miles Through KwaZulu-Natal

The Comrades Marathon isn't just an ultramarathon—it's a pilgrimage. Every June, roughly 20,000 runners gather in South Africa's KwaZulu-Natal province to tackle 56 miles (90 kilometers) of rolling hills between Durban and Pietermaritzburg. The route alternates direction each year: the "Up Run" from Durban to Pietermaritzburg, and the "Down Run" in reverse. But regardless of direction, every runner must grapple with a weather challenge unique to this race: 12 or more hours of variable conditions, from potentially cold pre-dawn starts to warm midday sun, across terrain that ranges from sea level to over 2,800 feet elevation. Understanding Comrades weather isn't just about comfort—it's about race execution and, for many runners, simply finishing within the 12-hour cutoff.

This guide covers everything about Comrades Marathon weather: historical conditions, how the Up and Down runs differ weather-wise, the altitude and terrain factors, managing a 12+ hour temperature swing, and strategies for one of the world's most iconic ultras.

Understanding Comrades Climate

When and Where

The setting for the challenge:

Timing:

Comrades is held in early June
This is late autumn/early winter in South Africa
Southern hemisphere seasons are opposite Northern
June in KwaZulu-Natal = transitional weather
Not extreme summer heat, not deep winter cold

The region:

KwaZulu-Natal province on South Africa's east coast
Durban is coastal, subtropical climate
Pietermaritzburg is inland, higher elevation
The route traverses between these climates
Weather changes with terrain and elevation

Typical June conditions:

Morning temperatures: 45-55°F (7-13°C)
Afternoon temperatures: 65-75°F (18-24°C)
Generally dry but rain possible
Variable cloud cover
Frost possible in the high points early morning

Historical Weather Patterns

What the race has seen:

The good years:

Cool, overcast conditions throughout
Temperatures staying in the 50s-60s
Light wind, no rain
These years produce fast times
The weather contributes to performance

The challenging years:

Warming significantly by midday
Direct sun exposure
Temperatures reaching 75-80°F
Heat accumulates over long race duration
These years test everyone

The memorable extremes:

Cold, rainy years have occurred
Hot, exposed years have occurred
Conditions vary significantly year to year
Climate change adds uncertainty
Prepare for multiple scenarios

The pattern:

Early morning: Generally cold to cool
Mid-morning: Warming begins
Midday and afternoon: Warmest period
Late afternoon: May cool slightly
The window of warmest weather hits mid-pack runners hardest

Up Run vs Down Run Weather

The Up Run (Durban to Pietermaritzburg)

When you start at the coast:

Starting conditions:

Begin in Durban near sea level
Coastal influence moderates temperature
Often humid from ocean proximity
Pre-dawn start is cool but not usually frigid
Sea level air is thicker (more oxygen)

Weather progression:

Climb away from coastal moderation
Gain 2,800+ feet of net elevation
Temperatures typically cooler at higher altitude
But climbing generates significant body heat
The work of climbing creates heat management challenges

The weather paradox:

Running uphill makes you hot
But you're climbing to where it's cooler
Net effect often balances
However, sun exposure increases with time
Warmth accumulates as the day progresses

Finishing conditions:

Pietermaritzburg is inland, higher
Afternoon temperatures can be warm
Less humidity than coastal start
May feel hot after hours of running
The climb's end doesn't mean the challenge ends

The Down Run (Pietermaritzburg to Durban)

When you start inland:

Starting conditions:

Begin in Pietermaritzburg at higher elevation
Early morning can be quite cold
Possible frost on cold years
Less humidity than coastal
May need more layers at the start

Weather progression:

Descend toward the coast
Temperatures typically rise as you lose elevation
Running downhill generates less heat than climbing
But you're heading into warmer air
And the day is warming anyway

The weather challenge:

Start cold, finish warm
Massive temperature swing possible
May start with jacket, finish in singlet
Coastal humidity returns toward end
The final miles can feel oppressive

Finishing conditions:

Durban's coastal location
Higher humidity
Usually warmer than the start
Sea level air feels thicker
Heat and humidity compound fatigue

Direction-Specific Strategies

Adapting to each direction:

For the Up Run:

Dress for the start but plan to shed layers
Accept that climbing will make you hot
Pace conservatively on uphills
Altitude gain helps with cooling somewhat
Focus on not overheating during the climbs

For the Down Run:

Dress warmly enough for cold start
Arm sleeves are ideal (easy to remove)
Know you'll warm up significantly
The final coastal miles may be hardest weather-wise
Prepare for heat at the finish

Gear flexibility:

Arm warmers: Essential for cold starts, easy to remove
Light jacket: Can tie around waist
Gloves: May want for first hours on cold years
Hat/visor: Sun protection for afternoon
Multiple options at aid stations

Altitude and Terrain Effects

The Elevation Profile

How terrain affects weather experience:

Up Run elevation:

Start: Sea level (Durban)
Highest point: ~2,900 feet (880m) before Pietermaritzburg
Net gain: Approximately 2,800 feet
Five major climbs, countless smaller ones
Each climb creates microclimate changes

Down Run elevation:

Start: ~2,200 feet (670m) in Pietermaritzburg
Lowest point: Sea level (Durban)
Net descent: ~2,200 feet
Same hills, reversed experience
Descending to warmth

The "Big Five" hills:

Cowies Hill, Fields Hill, Botha's Hill, Inchanga, Polly Shortts
Each has distinct character
Altitude changes affect temperature
Sun exposure varies with direction and time
Hill difficulty compounds weather effects

Microclimate Variations

How the course creates weather variety:

Valley bottoms:

Often cooler in early morning (cold air pools)
Can be warmer midday (heat trapped)
May have fog early
Temperature inversions possible
Brief relief from sun if shaded

Hilltops and exposed ridges:

More wind exposure
Cooler with breeze
But also more sun exposure
Can feel either better or worse
Depends on conditions

Forested sections:

Shade provides relief from sun
Temperature can be 5-10°F cooler
Cherish these sections on hot days
Some traditional shade spots known to regulars
Course knowledge helps

Urban sections:

Asphalt radiates heat
Less wind protection
Hotter on warm days
Crowd support provides distraction
Focus on forward progress

Managing 12+ Hours of Weather

The Time Challenge

What extended exposure means:

The scope:

Elite runners: 5-6 hours
Sub-10 hour runners: 7-10 hours
Back-of-pack runners: 10-12 hours
Most runners are out 8-11 hours
This is extraordinary weather exposure

Temperature swing:

May experience 20-30°F temperature change
Cold start to warm afternoon is typical
Clothing needs change dramatically
Hydration needs change
Pacing needs change

Cumulative effect:

Heat stress accumulates over hours
Early miles in heat have lasting impact
What feels fine at hour 3 may not at hour 10
Conservative early = stronger late
Respect the duration

Phase-Based Weather Strategy

Managing conditions through the race:

Phase 1: Pre-dawn to dawn (0-15km):

Coldest part of the race
Body still fresh, generating heat
Dress for cold but not excessive
Accept some initial chill
You'll warm up

Phase 2: Morning (15-42km):

Temperatures rising
Body working hard
May need to shed layers
Hydration becomes important
Watch for overheating

Phase 3: Midday (42-60km):

Potentially warmest conditions
Fatigue accumulating
Heat tolerance decreasing
Most critical hydration period
Ice, water over head, shade when available

Phase 4: Afternoon (60-90km):

May cool slightly toward end
But body is depleted
Heat effects cumulative
Finish line is motivation
Just keep moving forward

Aid Station Weather Management

Using support smartly:

Hydration at aid stations:

Drink at every station, not just when thirsty
Water over head and neck on warm days
Ice in hat if available
Electrolytes for long duration
Don't skip stations to save time

Clothing changes:

Aid stations offer drop bag access
Can change shirts (fresh, dry clothes feel amazing)
Add or remove layers as needed
Gloves off, hat on, or vice versa
Plan what goes in each drop bag based on expected conditions

Temperature assessment:

How hot am I right now?
What are conditions for next section?
Am I dressed appropriately?
Need to cool down or warm up?
Adjust at each opportunity

Race Day Preparation

Pre-Race Weather Analysis

Preparing for conditions:

Days before:

Monitor forecast obsessively
Note temperature range expected
Check wind forecast
Look at historical data for that date
Begin forming gear plan

Night before:

Final forecast check
Select primary clothing
Prepare backup options
Pack drop bags with alternatives
Accept whatever is coming

Race morning:

Check actual conditions
Confirm gear choices
Adjust if needed
Don't overdress out of pre-race cold
Trust your plan

Gear Selection

What to prepare:

Cold start essentials:

Long-sleeve base layer or arm warmers
Light gloves (disposable or stash-able)
Possibly ear covering
These can be removed as you warm

Sun and heat protection:

Visor or light cap
Sunscreen (multiple applications needed)
Light colors preferred
Minimal coverage when warm
Sunglasses if sensitive

The versatile choices:

Arm warmers: Best single piece for temperature variation
Buff/neck gaiter: Warmth or sun protection
Light singlet with arm warmers: Perfect combination
Clothes that can be tied or tucked

Drop bag strategy:

Different options at different points
Dry shirt for midway (psychological boost)
Adjust layers based on conditions
Nothing heavy—you'll need to carry it
Think about what the weather will be at that point

Historical Race Conditions

What Past Years Show

Learning from history:

Cool, favorable years:

Temperatures staying below 70°F throughout
Cloud cover reducing sun exposure
Low humidity conditions
These years have faster average times
Weather enables performance

Warm, challenging years:

Temperatures exceeding 75°F by midday
Clear skies with full sun exposure
High finish-line temperatures
Higher dropout rates
Weather becomes the opponent

Wet years:

Rain occurs occasionally
Usually light to moderate
Actually can help with cooling
But wet feet become issue over 56 miles
Requires different gear (waterproof layer option)

The variance message:

You cannot count on specific conditions
Prepare for the realistic range
Don't build your race plan around ideal weather
Adaptability is essential
Race the day you get

Lessons from Comrades History

What veterans know:

Patience in heat:

Hot years reward conservative pacing
Going out too hard in heat = disaster later
The race is long enough to recover from slow start
But not from early overheating
Experienced runners respect the conditions

Don't fight the weather:

You cannot will it to be cooler
Adjust expectations to conditions
A finish in bad weather is a victory
Time goals may need revision
Running Comrades is the achievement

The collective experience:

20,000 people experiencing the same conditions
Everyone is affected by the weather
Hot years are hard for everyone
Perspective helps psychologically
You're not alone in the struggle

Key Takeaways

Expect 20-30°F temperature swing. Plan clothing and pacing for cold starts and warm finishes.
Up and Down runs differ. Up runs climb into cooler air but work harder; Down runs descend into warmth.
12+ hours magnifies everything. Weather effects accumulate over the race duration; start conservative.
Arm warmers are essential. The single most versatile piece for managing temperature variation.
Hydrate at every aid station. The long duration and variable conditions make consistent hydration critical.
Conditions vary year to year. Prepare for both cool, overcast and warm, sunny scenarios.
Midday is most challenging. Mid-pack runners face peak heat at peak fatigue; respect this intersection.
Finishing is the accomplishment. Adjust time goals based on conditions; completing Comrades is the victory.

The Comrades Marathon is an ultramarathon in every sense—including weather endurance. Run Window can help you train in varied conditions, building the adaptability this legendary race demands.