Soil Temperature in Hilton Head Island, SC

Current soil temperature: 83°F at the 2-inch depth, 4.1°F above the historical average for this date. Measured July 3, 2026 at the Youmans Farm USDA station, 39 miles away.

SOIL TEMPERATURE · 2" DEPTH · JULY 3, 2026

4.1 degrees above historical average of 79 degrees Fahrenheit Flat over 7 days

2-inch depth (5 cm)

USDA sensor #2038 , 39 miles NW (Youmans Farm)

Confidence: MediumStation is 39.1 mi from your location, so readings may not exactly match your conditions

Last reading: July 3, 2026 (updated 2 days ago). USDA sensors publish with about a 1-day lag.

Advanced options (year, as-of date)

Recommendations

Planning the year

See Hilton Head Island schedule

Fertilizer

IN WINDOW

Warm-season summer nitrogen

A mid-summer nitrogen feeding sustains the bermudagrass or zoysia growth started in late spring, feeding the most active growth phase of the year. Skipping it leaves a thinner canopy heading into the late-summer disease and weed window. Shallow soil temperatures are in the action band at 83°F at 2 inches at the Youmans Farm sensor, 39 miles from your location.

Details for Warm-season summer nitrogen
Confidence	MODERATE CONFIDENCE

Additional detail

Trigger: 2-inch soil holds 75°F
Source: Youmans Farm station

Source: Youmans Farm station

Fertilizer

IN WINDOW

Summer iron (foliar) application

A foliar iron spray darkens the lawn's color without forcing the leaf growth a nitrogen feeding would, which is exactly what summer-stressed turf needs. Iron is taken up directly through the leaves, so results show in days rather than weeks. Shallow soil temperatures are in the action band at 83°F at 2 inches at the Youmans Farm sensor, 39 miles from your location.

Details for Summer iron (foliar) application
Confidence	MODERATE CONFIDENCE

Additional detail

Trigger: 2-inch soil holds 70°F
Source: Youmans Farm station

Source: Youmans Farm station

Pest Watch

IN WINDOW

Fall armyworm watch

Fall armyworms can strip a healthy lawn down to brown stems in days once the caterpillars are large enough to feed actively. Migration patterns make outbreaks unpredictable; watching for the first signs in late summer means you can treat before the damage is done. Shallow soil temperatures are in the action band at 83°F at 2 inches at the Youmans Farm sensor, 39 miles from your location.

Read our full pest watch guide

Details for Fall armyworm watch
Confidence	MODERATE CONFIDENCE

Additional detail

Trigger: 2-inch soil holds 70°F
Source: Youmans Farm station

Source: Youmans Farm station

Daily Soil Temperature

Depth: 2" • Last 12 Months

Showing chart

Nearest USDA Station

Youmans Farm (Site 2038), SC

Distance: 39 miles from Hilton Head Island, SC
Elevation: 75 ft
Coordinates: 32.6667, -81.2000

USDA NWCC AWDB soil temperature observations.

The 2-inch reading first crossed 50°F on Dec 10, when the pre-emergent window opened.
Date	2" °F	Δ 2"	4" °F	8" °F	20" °F	40" °F
Jul 3	82.8	+0.6	83.7	84.4	83.3	79.3
Jul 2	82.2	+0.3	83.1	84.2	83.3	79.3
Jul 1	81.9	0.0	82.8	84.0	83.1	79.2
Jun 30	81.9	+1.7	82.8	83.7	82.8	79.0
Jun 29	80.2	-3.1	81.0	82.2	82.6	79.0
Jun 28	83.3	+0.7	84.0	84.6	83.3	78.8
Jun 27	82.6	—	83.5	84.2	82.8	78.4

Soil temperature by depth

82.8°F

2 in · germination

83.7°F

4 in · root zone

84.4°F

8 in · deeper trend

83.3°F

20 in · deep soil

79.3°F

40 in · frost depth

Check the current soil temp at your location, or open the live US soil temperature mapto see today’s ground readings from 380+ USDA and NOAA stations across the country. Enter your ZIP code for live soil temperatures near you, plus planting windows, pre-emergent timing, fertilizer guidance, and disease watch alerts based on your nearest USDA monitoring station.

How Soil Temperature Drives Lawn Timing

About the Data

Readings refresh nightly from the USDA-NRCS Soil Climate Analysis Network and the NOAA US Climate Reference Network (USCRN). Readings are measured by in-ground sensors at federal monitoring stations, not estimated from weather models; see how we measure. Planting windows are derived from multi-year climatology overlaid with NOAA 1991–2020 frost normals. Recommendation cards evaluate current soil conditions against research-backed thresholds from university extension sources. Check back regularly as conditions change. The guidance updates with every new reading.

Data sources: USDA-NRCS SCAN network, NOAA USCRN, NOAA 1991–2020 climate normals, and localized frost climatology via Soil Temps analytics.

Browse soil temperature data by state, over 2,000 cities with current readings, hardiness zones, and planting windows.

Explore the US Soil Temperature Map for a live station view of readings across the country.

Soil Conditions in Hilton Head Island, SC

USDA Growing Zone

Zone 9B

Average First Frost

November 1

Elevation

75 ft

Cool-Season Viability

Warm-season only

This area favors warm-season grasses; cool-season grass struggles through the summer heat here. As of July 5, the 2-inch soil temperature is running 4°F above the 10-year normal for this date. Data comes from the USDA station at Youmans Farm, 39 mi away.

For established lawns and gardens, the 4 inch soil temperature is a more useful reading than the surface. This 4-inch root-zone depth changes more slowly than the 2-inch surface layer, so it is a steadier signal for timing fertilizer, aeration, and weed control. The depths your nearest station reports are shown above; stations in the federal network typically report 2, 4, 8, 20, and 40 inches, while modeled estimates for areas far from a station cover fewer depths.

When to apply pre-emergent herbicide →

View historical soil temperature data →

Soil Temperature FAQ

What soil temperature is needed to plant grass seed?

Cool-season grasses like fescue and bluegrass germinate best when soil at 2 inches stays between 50–65°F for several consecutive days. Warm-season grasses like Bermuda and Zoysia need soil temperatures of 65–70°F or higher before seeding.

How deep should I measure soil temperature?

Use 2 inches for germination decisions, since that is where seeds sit. Use the 4 inch soil temperature for established lawn and garden timing: it reads the root zone, changes more slowly than the surface, and is the depth most fertilizer, aeration, and disease guidance references. The 8 inch reading shows deeper root-zone trend. The 20 and 40 inch readings track deep soil and frost depth where federal stations report them.

What does the 4 inch soil temperature mean?

The 4 inch soil temperature shows conditions deeper in the root zone than the 2 inch germination reading. It is commonly used for established lawn, garden, and agricultural timing because it changes more slowly than the surface layer, so it is a steadier signal for fertilizer, aeration, and weed-control decisions.

What’s the difference between soil temperature and air temperature?

Soil changes temperature much more slowly than air due to thermal mass. A warm afternoon does not mean the ground is warm. Soil temperature lags air temperature by days or weeks, making it a more reliable indicator of when biological processes like germination actually begin.

When should I apply pre-emergent based on soil temperature?

Apply pre-emergent herbicide when soil at 2 inches reaches 55°F for several consecutive days. This is the threshold where crabgrass and other summer annual weeds begin germinating. Applying after this point reduces effectiveness significantly.

What is a USDA Plant Hardiness Zone?

USDA Plant Hardiness Zones divide the US into 13 zones based on average annual extreme minimum temperature. They help determine which plants and grasses can survive winter in your area. Zone numbers increase from coldest (1a) to warmest (13b).

Grass seed germination

Your soil near Hilton Head Island, SC: 83°F at 2 inches, as of July 3, 2026.

Grass species	Germination optimum	Days	Right now
Bermudagrass	75–85°F	10-30	Germinates well
Zoysia	75–85°F	varies	Germinates well
Buffalograss	75–85°F	14-30	Germinates well
Centipede	75–85°F	varies	Germinates well
Kentucky bluegrass	59–86°F	14-30	Germinates, but warm for establishment

See all species and the full germination guide →

This week’s watering for Hilton Head Island, SC

Ease off: about 0.65 inches tops off what the rain will leave short

Weekly target	1.25 in	at 83°F soil, for warm-season grass
Expected rain	0.6 in	over the next 7 days
You supply	0.65 in	in 2 deep sessions, watered 4-9 AM

The weekly target includes rainfall, so irrigation only covers the deficit. Water deeply and infrequently rather than a little every day: shallow daily watering builds shallow roots and invites disease. Rainfall is a modeled forecast estimate for this location.

How to water by soil temperature, and audit your sprinklers →

Lawn disease risk

The 7-day forecast near Hilton Head Island, SC favors active disease pressure. These diseases are the ones to watch now. Based on a modeled weather estimate for this location.

Disease	Risk	Why now
Pythium blight (Pythium spp.)	Favorable	7 of the next 7 nights stay above 65°F with hot days; worse with excess nitrogen. Water early morning to limit leaf wetness, hold nitrogen to 0.25 lb/1,000 sq ft, and fix drainage in low spots. The fastest killer, 2-3 days.

How temperature drives lawn disease, and the cultural fixes →

Growing degree days near Hilton Head Island, SC

2,712GDD (base 50°F) since January 1, through July 3

83°Fcurrent soil temperature

Growing degree days measure the heat a lawn has accumulated this year: each day adds the amount its average temperature runs above 50°F, the point where cool-season growth and most pests get going. Turf managers use the running total to time crabgrass pre-emergent, annual bluegrass seedhead suppression, and grub control. Pairing it with the current soil temperature shows both the season's heat so far and what the ground is doing right now. Measured at the NOAA station Blackville 3 W.

What growing degree days are and how to use them for lawn-care timing →