Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 17868 — Riverside, PA

ZIP code 17868 (Riverside, Northumberland County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 30 and the first fall frost October 13.

Where ZIP 17868 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 30
First frostOct 13
2012 zone6b

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Riverside, PA…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Riverside, PA

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 30median — 50% chance of a later frost
Safe for tender plantsMay 19only 10% chance of frost after
First fall frostOctober 13median — 10% chance by Sep 30
Growing season166 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 14 and returns around October 26.

From the NOAA station Sunbury, PA — 11 miles away, elevation 574 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 17868

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 19 – Apr 2
SpinachSow outdoors · Mar 19 – Apr 9
Broccoli, cabbageStart indoors · Feb 19 – Mar 5
Broccoli, cabbageTransplant · Apr 9 – Apr 23
Onion setsPlant outdoors · Apr 2 – Apr 16
PotatoesPlant outdoors · Apr 9 – Apr 23
LettuceSow outdoors · Apr 2 – Apr 16
Carrots, beetsSow outdoors · Apr 9 – Apr 23
TomatoesStart indoors · Mar 5 – Mar 19
TomatoesTransplant · May 7 – May 21
Peppers, eggplantStart indoors · Feb 19 – Mar 5
Peppers, eggplantTransplant · May 14 – May 28
BeansSow outdoors · May 7 – May 21
Sweet cornSow outdoors · May 7 – May 21
Cucumbers, squashSow outdoors · May 7 – May 21
Fall lettuce, spinachSow outdoors · Aug 18 – Sep 1
GarlicPlant cloves · Sep 29 – Nov 3
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 30) and first fall frost (Oct 13) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 17868 came on Mar 31 — 4 days earlier than the 1991–2020 average (Apr 4).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 6b in Pennsylvania

605 plants native to the lower 48 states, recorded in Pennsylvania, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. Each links to its USDA PLANTS profile.

Trees 76

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 122

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 209

alkali buttercup1 ft · blooms late spring · low shade tolerance · to −38 °FAmerican bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °F

Grasses 173

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °FAtlantic mannagrass3 ft · blooms summer · low shade tolerance · to −8 °Fautumn bluegrass1.5 ft · blooms late spring · medium shade tolerance · to −8 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °FBailey's sedge2.1 ft · blooms late spring · low shade tolerance · to −33 °F

Vines 10

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Riverside, PA.

Soil in Riverside, PA

The soil mapped at the center of ZIP 17868 is Wyoming — gravelly sandy loam, somewhat excessively drained.

TextureGravelly sandy loamdrains and warms fast; dries out and needs more feeding
pH4.8strongly acidic; most vegetables like 6.0–7.0
DrainageSomewhat excessively drainednatural drainage class
Organic matter3%moderate
Hydrologic groupAwater soaks in fast
Farmland classFarmland of statewide importanceUSDA classification

Map unit: Wyoming gravelly sandy loam, 3 to 8 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 17868; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Riverside, PA

Summer high84 °Faverage high, July
Winter low19 °Faverage low, January
Hot days16days a year at 90 °F or more
Freezing nights134nights a year at 32 °F or less
Growing degree days2,859base 50 °F — the season’s usable heat
Longest day15 h 07 mindaylight on June 21
Shortest day9 h 13 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation41.6 inper year, rain and melted snow
Snowfall29 inper year

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 35 °F, low 19 °F 35°19° JanFebruary: average high 39 °F, low 21 °F 39°21° FebMarch: average high 48 °F, low 27 °F 48°27° MarApril: average high 61 °F, low 37 °F 61°37° AprMay: average high 72 °F, low 47 °F 72°47° MayJune: average high 80 °F, low 57 °F 80°57° JunJuly: average high 84 °F, low 60 °F 84°60° JulAugust: average high 82 °F, low 59 °F 82°59° AugSeptember: average high 75 °F, low 51 °F 75°51° SepOctober: average high 64 °F, low 40 °F 64°40° OctNovember: average high 51 °F, low 32 °F 51°32° NovDecember: average high 40 °F, low 25 °F 40°25° Dec

Precipitation by month inches · ❄ = snowfall

0″1″2″3″4″5″January: 3.60 in precipitation, 10.1 in snowfall 3.6❄10 JanFebruary: 2.07 in precipitation, 7.3 in snowfall 2.1❄7 FebMarch: 3.27 in precipitation, 5.9 in snowfall 3.3❄6 MarApril: 3.80 in precipitation, 0.7 in snowfall 3.8❄1 AprMay: 3.41 in precipitation 3.4 MayJune: 3.94 in precipitation 3.9 JunJuly: 3.47 in precipitation 3.5 JulAugust: 3.30 in precipitation 3.3 AugSeptember: 4.66 in precipitation 4.7 SepOctober: 3.93 in precipitation, 0.2 in snowfall 3.9 OctNovember: 2.91 in precipitation, 0.4 in snowfall 2.9 NovDecember: 3.21 in precipitation, 4 in snowfall 3.2❄4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Sunbury, PA (11 mi away); precipitation: Danville, PA (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

178226b
Danville, PA · 2 mi
178216b
Danville, PA · 2 mi
178846b
Washingtonville, PA · 7 mi
178576b
Northumberland, PA · 8 mi
178606b
Paxinos, PA · 8 mi
178656b
Potts Grove, PA · 9 mi
178246b
Elysburg, PA · 9 mi
178476b
Milton, PA · 10 mi

Pennsylvania planting zones →

Questions about 17868

What planting zone is ZIP code 17868?

ZIP code 17868 (Riverside, PA) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Riverside, PA?

The median last spring frost (32 °F) near 17868 is April 30; after May 19 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Sunbury station.

When is the first frost in Riverside, PA?

The median first fall frost near 17868 is October 13, giving a median frost-free growing season of 166 days.

When should I plant tomatoes in 17868?

Start tomato seeds indoors around Mar 5 – Mar 19 and set transplants outside around May 7 – May 21, one to three weeks after the median last frost.

How much rain and snow does 17868 get?

About 41.6 inches of precipitation a year and 29 inches of snowfall (NOAA 1991–2020 normals, Danville station).

How hot do summers get in Riverside, PA?

The average high peaks at 84 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 17868 have?

The USDA soil survey maps Wyoming at the center of ZIP 17868: gravelly sandy loam, somewhat excessively drained, pH about 4.8 (strongly acidic).

Did spring come early in Riverside, PA in 2026?

Spring leaf-out near 17868 came on Mar 31 in 2026, 4 days earlier than the 1991–2020 average (Apr 4), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Riverside, PA?

Long-day onions: the longest day near 17868 is 15 h 07 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).