Weather StoryAlmanac, microseasons, and the day's weather story.

Weather in Grinnell, Iowa

Roses Bloom Along the Shelter Rows. Day 59 of spring. Read this microseason across nine climate regions →

Grinnell, IA
Sunday, May 17 at 12:53 AM
78
°
Overcast
Feels like
79°
Humidity
64%
Wind
10 mph
Sunrise
5:49 AM
Sunset
8:24 PM
Grinnell, IA
Hour by hour · 24h
74°
7p
72°
8p
70°
9p
69°
10p
66°
11p
65°
12a
63°
1a
63°
2a
62°
3a
60°
4a
57°
5a
57°
6a
58°
7a
62°
8a
66°
9a
70°
10a
74°
11a
78°
12p
82°
1p
84°
2p
85°
3p
86°
4p
86°
5p
83°
6p
L 57°H 86°
Grinnell, IA
7-day forecast
  1. Today
    May 16
    Thunderstorm
    66%
    82°58°
  2. Sunday
    May 17
    Thunderstorm
    55%
    79°61°
  3. Monday
    May 18
    Thunderstorm
    85%
    82°62°
  4. Tuesday
    May 19
    Light Showers
    82%
    64°46°
  5. Wednesday
    May 20
    Overcast
    60°40°
  6. Thursday
    May 21
    Overcast
    64°44°
  7. Friday
    May 22
    Overcast
    66°52°
Grinnell, IA
Anemometer · 24h winds · from true
NESW
From · True
SSE
154° · backing 39°
Direction
SSE
154°
Sustained
10
mph
Gust
20
mph
Peak 24h
45
avg 7
Beaufort · 3 · GENTLE BRZ
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 7 · pk 45 @ 11:00p
−24h−18h−12h−6hnow
Light breeze backing 39° from the sse.
Grinnell, IA
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
972.2
-0.8 mb in 3h · falling · 28.71 inHg
Now
972.2
mb
3h
-0.8
mb
12h
-2.4
mb
24h
+1.5
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 971975
−24h−18h−12h−6hnow
Deep low — expect rough seas, strong wind, and persistent rain.
Grinnell, IA
Air quality
54
AQI
Moderate
PM 2.5
4.0 μg/m³
PM 10
5.0 μg/m³
NO₂
2.5 μg/m³
Ozone
94.0 μg/m³
UV Index
0.1 Low
Grinnell, IA
Almanac · Sunday, May 17
When the dew is on the grass, rain will never come to pass.
Civil dawn
10:19 AM
Sunrise
5:49 AM
Daylight
14h 35m
Sunset
8:24 PM
Civil dusk
1:57 AM
Planting note
Direct sow okra, melons, and southern peas. Thin carrot rows.
Grinnell, IA
The moon
New Moon
0% illuminated
Moonrise
10:53 AM
Moonset
1:58 AM
In sign
♉︎ Taurus
Grinnell, IA
Microseason · 28 of 72
May 16–20

Roses Bloom Along the Shelter Rows

plant
Jan 137% of the yearDec 31

Read this microseason across nine climate regions →

Grinnell at a glance

  • Today vs. normal: 8°F above the seasonal normal for this latitude
  • Last frost: April 26 (climatological average for this latitude)
  • Microseason: 28 of 72, May 16–20
  • Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.

Right now in the garden

Warm-season window is open

As of May 17, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.

ZIP codes in Grinnell

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.