August is the late-summer peak of heat in Oklahoma, but the season begins to turn — scissor-tails mass on the wires, shorebirds pour through the salt flats, and the prairie golds with sunflowers. Nights bring the Perseids over dark skies.
Week by week in August
July 30 – August 5
- Scissor-tailed Flycatchers mass in large pre-migration flocks on the wires, dozens to hundreds gathering at dusk.
- Watermelons and cantaloupe are at their best as winter squash and the first pumpkins begin to appear.
- The migratory monarch generation begins to appear, fueling on nectar for the journey to Mexico.
- Set out fall tomato and pepper transplants and start cool-season broccoli, cabbage, and root crops by late month.
August 6–12
- The Perseid meteor shower peaks around August 12, the year's best for warm late-night viewing from a dark site.
- Salt Plains and Hackberry Flat host the fall shorebird peak with avocets, stilts, and a sweep of sandpipers.
- Native sunflowers light up roadsides and field edges as the first goldenrods and asters begin opening.
- Tomatoes, okra, and sweet corn crowd the tables at peak summer abundance across the state.
August 13–19
- Mississippi kites flock and begin drifting south, and purple martins stage in big roosts before departing.
- The first directional southbound monarchs cross Oklahoma, the front edge of the great fall passage.
- Cardinal flower scarlet peaks in eastern seeps as ironweed and blazing star color the tallgrass prairie.
- Direct-sow fall greens, carrots, and beets, keeping the soil moist and shaded to germinate seed in the heat.
August 20–26
- Ruby-throated hummingbirds surge at feeders as migrants pour through, building fat for the southward journey.
- Maximilian sunflower begins its tall yellow spires as snow-on-the-mountain shows its green-and-white bracts.
- Pecans carry full-sized green nuts and the first early-turning sumacs flush red along the fencerows.
- Sweet potatoes begin to dig and the first early apples and pears arrive alongside the late melons.
August 27 – September 2
- The queen butterfly wanders north into Oklahoma and nectars alongside the building monarch migration.
- The Milky Way arches at its best from the Sagittarius core through the Summer Triangle overhead.
- The first Franklin's gulls stream across the prairie and broad-winged hawks ride south on the thermals.
- Keep planting cool-season crops and harvesting summer produce; the fall garden is fully underway.
Birds This Month
August is when fall migration takes hold in Oklahoma even as summer lingers. Scissor-tailed Flycatchers begin massing in large pre-migration flocks on the wires and in shelterbelts — gatherings of dozens to hundreds are a spectacular late-summer Oklahoma sight before they head south. Mississippi kites also flock and begin drifting south, and purple martins stage in big roosts before departing.
The salt flats and mudflats come alive with southbound shorebirds: Salt Plains and Hackberry Flat host American avocets, black-necked stilts, least, pectoral, Baird's, and stilt sandpipers, yellowlegs, and the chance of rarer species at the peak of fall shorebird passage. Wood storks occasionally wander north to the south-central reservoirs. The first songbird migrants — warblers, orioles, and flycatchers — begin trickling through the eastern woods.
Ruby-throated hummingbirds surge at feeders as migrants pour through, building fat for the journey. Keep feeders clean and full now.
This month's tip: visit Salt Plains or Hackberry Flat for the shorebird peak, and watch the rural wires at dusk for the gathering scissor-tail flocks — August offers both the last of summer's breeders and the first rush of fall.
What's Blooming
August wildflowers shift to gold as the prairie summer matures. Native sunflowers — the common annual and the perennial Maximilian beginning late in the month — light up roadsides and field edges, joined by partridge pea, snow-on-the-mountain's green-and-white bracts, and the deep purple of ironweed and tall blazing star. The first goldenrods and early asters begin opening, the heralds of autumn.
The tallgrass prairie is at its tallest now, the big bluestem heading out above the flowers, with rosinweed, compass plant, button blazing star, and tall thistle standing among the grass. Wet ground shows cardinal flower's brilliant scarlet in the eastern seeps and ditches, working hummingbirds, alongside swamp milkweed and great blue lobelia.
Where to see it: the Tallgrass Prairie Preserve shows the late-summer prairie towering and gold with sunflowers and blazing star. Eastern stream banks and wet ditches reward a search for the scarlet cardinal flower, one of the most striking native blooms of the Oklahoma late summer.
Garden This Month
August is the pivot to fall in the Oklahoma garden, even at the peak of the heat. The summer crops — okra, southern peas, peppers, eggplant, sweet potatoes, and melons — keep producing, and tomatoes that stalled in July often set fruit again as nights ease. But the defining task now is planting the fall garden: set out fall tomato and pepper transplants at the start of the month, direct-sow another round of green beans, summer squash, and cucumbers, and by mid-to-late August begin the cool-season crops — broccoli, cabbage, collards, carrots, beets, turnips, and lettuce.
Getting seeds to germinate in the August heat is the trick: sow a little deeper, keep the soil consistently moist with light frequent watering or shade cloth until seedlings are up, and mulch well. Keep harvesting the summer crops to maintain production, and stay vigilant on spider mites, grasshoppers, and squash bugs, which are at their worst now. A fall garden planted in this hot window will produce richly through Oklahoma's long, mild autumn.
Zone 7a (central and northeastern Oklahoma): the fall garden goes in now. Set out fall tomato and pepper transplants early in the month, and direct-sow green beans, squash, cucumbers, and by late August the cool-season crops — broccoli, cabbage, carrots, beets, and greens — keeping new sowings watered and shaded against the heat.
Zone 7b (south-central and southeastern Oklahoma): the long warm season gives a generous fall window. Plant fall tomatoes, beans, and squash, then start cool-season greens, broccoli, and root crops late in the month; shade and steady water are essential to get tender seedlings up in the August heat.
What's at the Farmers Market
August markets stay at peak summer abundance across Oklahoma. Tomatoes, okra, sweet corn, peppers, eggplant, cucumbers, summer squash, green beans, and southern peas all crowd the tables, and the famous Oklahoma melons are at their best — Rush Springs watermelons and sweet cantaloupe by the truckload. Porter peaches continue, joined by grapes and the first early apples and pears.
This is also the start of winter squash and the first pumpkins, alongside sweet potatoes beginning to dig, plentiful onions, garlic, and summer herbs, and bright cut flowers — sunflowers, zinnias, and celosia. Farm eggs and local honey remain steady through the late summer.
For selection and storage: choose watermelons by a creamy ground spot and a hollow thump, and cantaloupe by a sweet fragrance and slight give at the stem, keeping whole melons at cool room temperature. Hold tomatoes at room temperature stem-side down, refrigerate corn cold in the husk and use it quickly, and store okra, beans, and squash dry in the refrigerator for just a few days. Keep onions, garlic, and curing winter squash cool, dark, and dry.
Night Sky This Month
August brings warm nights, earlier darkness, and the year's most popular meteor shower to Oklahoma's dark skies. The remote Black Mesa country and Black Mesa State Park in the far panhandle offer the state's blackest skies, and the open Wichita Mountains near Lawton give central Oklahoma a fine, accessible dark horizon; clubs around Tulsa and Oklahoma City hold Perseid watch parties when the late-summer haze clears.
The Milky Way stands at its glorious best, arching from the Sagittarius and Scorpius core in the south straight up through the Summer Triangle of Vega, Deneb, and Altair overhead and on into Cassiopeia in the northeast. From a truly dark Oklahoma site the galaxy casts a faint glow and shows its dark rifts to the naked eye.
The Perseid meteor shower, the summer's highlight, peaks around August 12, often producing dozens of meteors an hour from a dark site, radiating from the northeast after midnight. It is the year's best shower for warm, comfortable late-night viewing. For this year's exact Perseid peak, moon phase, and planet positions from your Oklahoma latitude, see the printable Oklahoma night-sky guide.
Butterflies & Pollinators
August butterflies are abundant and begin shifting toward the great migration. The prairies and gardens hold peak numbers of variegated fritillaries, common buckeyes, sulphurs, painted and American ladies, and many skippers on the sunflowers and blazing star. Swallowtails — eastern tiger, black, and giant — and the southern Gulf fritillary work the late-summer blooms, and snout butterflies can appear in numbers around hackberry.
The signature event is the building monarch migration: the final summer generation, the long-lived migratory monarchs, begins to appear, fueling up on nectar to make the journey to Mexico. By late August the first directional southbound monarchs cross Oklahoma, the front edge of the September-October passage. The queen butterfly, a southern monarch relative, also wanders north into Oklahoma now and nectars alongside its cousins.
To make the most of the season: August is the time to prepare for the monarch peak — keep late-summer nectar like sunflower, blazing star, zinnia, and milkweed blooming, and avoid mowing milkweed stands, which the migratory generation still uses. Warm mornings on a flower-rich roadside or prairie reward an August butterfly walk.
What to plant for them is in the Oklahoma native plants guide
Trees This Month
August holds the Oklahoma woods in deep, dusty late-summer green, and the first subtle hints of the turning year appear. The crape myrtles still bloom in town, and in southeastern bottoms the native devil's walkingstick and buttonbush finish flowering. Stressed trees on the dry plains — cottonwoods, hackberries, walnuts, and sycamores — show scorched leaf margins and shed early leaves in drought, dropping the first brown litter of the season.
The trees' fruit and nuts are filling and ripening. The pecans have full-sized green nuts swelling toward fall in the bottomland groves, the oaks carry developing acorns, the persimmons ripen toward their first orange in the southeast, and the native black walnuts hang heavy with green husks. The eastern red cedars show their blue-green cones coloring up. Watch for the very first early-turning trees — a stressed sumac flushing red or a walnut going yellow — the earliest whispers of the autumn color still six weeks away.
The Oklahoma native plants guide covers what grows with them
Weather & Daylight
Across Oklahoma, a typical August day averages a high near 93°F and a low near 69°F, with about 3.2 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Still sweltering in the low 90s with steamy 69F nights, the air heavy and close under recurring afternoon downpours.
| Average high | 93°F |
|---|---|
| Average low | 69°F |
| Precipitation | 3.2 in |
| Sunrise (mid-month) | 6:47 CT |
| Sunset (mid-month) | 20:19 CT |
Figures are statewide averages over the 1991–2020 U.S. climate normals; local conditions vary with elevation and distance from the coast. Sunrise and sunset are computed for a midstate point on the 15th (CT).
Next month's version of this page, by email
One short note when Oklahoma's next month turns — what's arriving, blooming, and worth a night outside.
Go deeper with the Oklahoma guides
The complete Oklahoma birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: August in Oregon · August in Pennsylvania · August in Rhode Island