Understanding Humidity

The Invisible Element of Successful Husbandry

When new keepers begin researching jumping spider care, humidity is often one of the first topics they encounter—and one of the most misunderstood.

Some care guides suggest constant misting. Others recommend keeping enclosures nearly dry. The truth is that humidity is not a single number to chase, but rather one part of a balanced environment that includes ventilation, hydration, temperature, and species-specific needs.

Understanding humidity will help you create healthier enclosures, support successful molts, and avoid many of the problems that frustrate new keepers.

What Is Humidity?

Humidity refers to the amount of moisture present in the air.

The percentage commonly displayed on hygrometers is called:

Relative Humidity (RH)

Relative humidity measures how much moisture the air is holding compared to the maximum amount it could hold at that temperature.

For example:

  • 30% RH = Relatively dry air

  • 50% RH = Moderate humidity

  • 80% RH = High humidity

Why Humidity Matters

Humidity affects several important aspects of a spider's life.

Hydration

Jumping spiders absorb moisture primarily through drinking water droplets rather than directly from humid air.

However, proper humidity helps prevent dehydration and supports overall health.

Molting

Adequate humidity is especially important during molting.

Moisture helps:

  • Soften the old exoskeleton

  • Support successful molts

  • Reduce complications during shedding

Enclosure Stability

Proper humidity contributes to a healthier enclosure environment when balanced with ventilation.

Humidity vs Hydration

One of the biggest misconceptions in the hobby is that humidity and hydration are the same thing.

They are not.

Humidity

Moisture in the air.

Hydration

Water available for the spider to drink.

A spider can live in moderate humidity while still having access to fresh drinking water.

In many cases, hydration opportunities are more important than maintaining an exact humidity percentage.

The Ventilation Balance

Humidity without ventilation creates problems.

Poor airflow can lead to:

  • Mold growth

  • Bacterial buildup

  • Stagnant air

  • Unhealthy enclosure conditions

Good husbandry always seeks balance between:

Humidity

Ventilation

A slightly lower humidity level with excellent airflow is often healthier than high humidity with poor ventilation.

Humidity Requirements by Species

Not all jumping spiders require identical conditions.

Bold Jumping Spider

(Phidippus audax)

Recommended Humidity:

40–60%

Generally tolerant of slightly drier conditions.

Regal Jumping Spider

(Phidippus regius)

Recommended Humidity:

50–70%

Moderate humidity works well for most individuals.

Canopy Jumping Spider

(Phidippus otiosus)

Recommended Humidity:

60–75%

Often benefits from slightly higher humidity levels.

Mustache Jumping Spider

(Phidippus mystaceus)

Recommended Humidity:

50–70%

Moderate humidity with excellent airflow.

Shadow Jumping Spider

(Phidippus adumbratus)

Recommended Humidity:

45–65%

Avoid excessively damp conditions.

Fartilis Jumper

(Paraphidippus fartilis)

Recommended Humidity:

55–75%

Moderate humidity combined with good ventilation.

Giant Malaysian Jumper

(Hyllus diardi)

Recommended Humidity:

60–80%

Higher humidity is generally preferred due to their tropical origins.

Signs Humidity May Be Too Low

Potential indicators include:

  • Difficulty molting

  • Persistent dehydration

  • Reduced activity

  • Wrinkled abdomen appearance

These signs may also have other causes, so evaluate the spider's overall condition.

Signs Humidity May Be Too High

Excessive humidity often creates more problems than insufficient humidity.

Watch for:

  • Condensation on enclosure walls

  • Mold growth

  • Stale odors

  • Constantly wet substrate

  • Poor airflow

If these occur, ventilation should be addressed immediately.

Misting: Less Is Often More

Many beginners assume they should heavily mist every day.

In reality:

Light misting is usually sufficient.

The goal is to provide:

  • Drinking opportunities

  • Temporary moisture

  • Environmental stability

Not a constantly wet enclosure.

Humidity During Molting

Molting is the stage when humidity becomes most important.

Many keepers provide slightly elevated moisture opportunities during premolt periods while still maintaining proper airflow.

Common premolt signs include:

  • Refusal of food

  • Increased webbing

  • Reduced activity

  • Retreat construction

Once molting begins, avoid disturbing the spider.

Common Humidity Mistakes

Chasing Exact Numbers

Humidity naturally fluctuates throughout the day.

Focus on overall husbandry rather than obsessing over individual readings.

Over-Misting

More water does not always equal healthier conditions.

Ignoring Ventilation

Humidity and airflow must work together.

Relying Entirely on Humidity

Hydration opportunities remain essential.

The Tiny Coven Approach

At Tiny Coven Jumpers, we view humidity as part of a larger husbandry system rather than a single number to maintain.

Healthy spiders require:

✓ Appropriate hydration

✓ Good ventilation

✓ Stable temperatures

✓ Proper feeding

✓ Species-appropriate conditions

When these factors work together, humidity becomes much easier to manage.

A Keeper's Rule of Thumb

Provide water. Maintain airflow. Observe your spider.

The enclosure should never feel like a swamp, nor should it feel like a desert.

The goal is balance.

And as with all aspects of husbandry, your spider will often tell you more than a humidity gauge ever can.