Round Lake weather
Temperature, rain and wind in Round Lake (Illinois, United States), a city of about 18,461 people: how it is right now, hour by hour into tomorrow, the next 7 days and what each month of the year is like.
This page is not in Google’s index: the city is small, or it gets the same forecast as a large city next to it.
Right now
Friday 16 October, 00:00 (America/Chicago)
57 °F
Partly cloudy
Feels like
53 °F
Humidity
94%
Wind
16 mph
WNW · Beaufort 4
Dew point
55 °F
Cloud cover
77%
Pressure
1,009 hPa
Hour by hour
Next 24 hours, in the city’s local time.
| Time | Conditions | Temperature | Rain | Wind |
|---|---|---|---|---|
| 00:00 | Partly cloudy | 57 °F | 0.00 in | 16 mph |
| 01:00 | Partly cloudy | 55 °F | 0.00 in | 18 mph |
| 02:00 | Partly cloudy | 54 °F | 0.00 in | 19 mph |
| 03:00 | Partly cloudy | 52 °F | 0.00 in | 18 mph |
| 04:00 | Fair | 51 °F | 0.00 in | 15 mph |
| 05:00 | Partly cloudy | 51 °F | 0.00 in | 14 mph |
| 06:00 | Cloudy | 51 °F | 0.00 in | 14 mph |
| 07:00 | Cloudy | 51 °F | 0.00 in | 14 mph |
| 08:00 | Cloudy | 51 °F | 0.00 in | 14 mph |
| 09:00 | Partly cloudy | 50 °F | 0.00 in | 13 mph |
| 10:00 | Cloudy | 52 °F | 0.00 in | 17 mph |
| 11:00 | Light rain | 51 °F | 0.00 in | 16 mph |
| 12:00 | Rain | 51 °F | 0.01 in | 18 mph |
| 13:00 | Rain | 52 °F | 0.02 in | 20 mph |
| 14:00 | Light rain | 52 °F | 0.00 in | 18 mph |
| 15:00 | Light rain showers | 53 °F | 0.00 in | 19 mph |
| 16:00 | Fair | 52 °F | 0.00 in | 19 mph |
| 17:00 | Fair | 52 °F | 0.00 in | 18 mph |
| 18:00 | Fair | 51 °F | 0.00 in | 16 mph |
| 19:00 | Clear sky | 49 °F | 0.00 in | 15 mph |
| 20:00 | Clear sky | 48 °F | 0.00 in | 15 mph |
| 21:00 | Clear sky | 47 °F | 0.00 in | 14 mph |
| 22:00 | Clear sky | 46 °F | 0.00 in | 13 mph |
| 23:00 | Clear sky | 44 °F | 0.00 in | 12 mph |
Next 7 days
| Day | Conditions | Low | High | Rain outlook |
|---|---|---|---|---|
| Fri 16/10 | Rain | 40 °F | 57 °F | rain possible · 0.04 in |
| Sat 17/10 | Clear sky | 39 °F | 55 °F | no rain expected · 0.00 in |
| Mon 19/10 | Fair | 44 °F | 62 °F | no rain expected · 0.00 in |
| Tue 20/10 | Clear sky | 46 °F | 65 °F | no rain expected · 0.00 in |
| Wed 21/10 | Clear sky | 48 °F | 66 °F | no rain expected · 0.00 in |
| Thu 22/10 | Clear sky | 49 °F | 69 °F | no rain expected · 0.00 in |
| Fri 23/10 | Cloudy | 53 °F | 64 °F | no rain expected · 0.00 in |
This column is our own reading: the global model does not publish a probability of precipitation for this region, so we classify the day from the forecast symbol and the total in millimetres. It is not an official probability figure.
America/Chicago
What each number means
- Rain (mm)
- 1 millimetre of rain is 1 litre of water per square metre. Up to 2 mm in a day is drizzle; from 10 mm it is proper rain; more than 50 mm in a few hours is the amount that floods streets.
- Humidity
- Relative humidity is how much water vapour the air holds compared with the most it can hold at that temperature. Above 80% sweat evaporates slowly and heat feels worse; below 30% your throat and eyes dry out.
- Dew point
- The dew point is the temperature at which the air would start to condense. The closer it is to the air temperature, the muggier it feels. Above 20 °C the air already feels heavy.
- Feels like
- "Feels like" combines temperature, wind and humidity: strong wind carries heat away from the body, so it feels colder than the thermometer; high humidity in the heat makes it feel warmer.
- Wind
- Wind is given as a speed and the direction it blows from. Up to 20 km/h you barely notice it; at 40 km/h it moves branches and parasols; above 60 km/h it brings down trees and roof tiles.
- Cloud cover
- Cloud cover as a percentage is how much of the sky is covered. Up to 20% is a clear sky; above 80% the sun barely gets through.
- Chance of rain
- The model does not publish a probability of precipitation for this region. This column is our own reading: the global model does not publish a probability of precipitation for this region, so we classify the day from the forecast symbol and the total in millimetres. It is not an official probability figure.
Month-by-month climate
In October, Round Lake averages 51 °F and about 3.3 in of rain over the month, on the 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025) climatology.
Warmest month
July
Coldest month
January
Wettest month
June
Driest month
January
| Month | Mean temperature | Rain | Mean humidity |
|---|---|---|---|
| January | 21 °F | 1.7 in | 88% |
| February | 23 °F | 1.8 in | 85% |
| March | 35 °F | 2.4 in | 80% |
| April | 46 °F | 3.6 in | 77% |
| May | 57 °F | 4.4 in | 78% |
| June | 67 °F | 4.8 in | 77% |
| July | 73 °F | 3.9 in | 74% |
| August | 72 °F | 4.1 in | 74% |
| September | 64 °F | 3.7 in | 75% |
| October | 51 °F | 3.3 in | 77% |
| November | 38 °F | 2.2 in | 81% |
| December | 27 °F | 2.2 in | 88% |
Frequently asked questions
- Will it rain tomorrow in Round Lake?
- no rain expected. Rain: 0.00 in. Low 39 °F, High 55 °F.
- What is the temperature in Round Lake right now?
- 57 °F, partly cloudy. Feels like: 53 °F. Humidity: 94%.
- What will the weather be like at the weekend in Round Lake?
- Sat 17/10: clear sky, 39 °F / 55 °F, no rain expected.
- Which is the wettest month in Round Lake?
- June — ~4.8 in (25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025), NASA POWER).
- How far ahead does this Round Lake forecast go?
- This page shows 7 days. The model run used here is from 16/10/2026, 05:21 UTC, and the page fetches a new one every 30 minutes.
Nearby cities
Forecasts for places near Round Lake:
- Round Lake Beach 2 km
- Grayslake 4 km
- Mundelein 12 km
- Libertyville 14 km
- McHenry 14 km
- Gurnee 16 km
- Lake Zurich 17 km
- Vernon Hills 18 km
How to read this page
How to read the min and the max
The week’s high (69 °F) arrives in the afternoon, about two hours after solar noon; the low (39 °F) just before sunrise. Both are air temperature in the shade, two metres above ground — in direct sun or over asphalt a thermometer reads higher.
Where this number comes from
The Round Lake forecast comes from MET Norway, a partir do ECMWF HRES e, na área nórdica, do MEPS, run of 16/10/2026, 05:21 UTC. The month-by-month climate comes from NASA POWER, climatology of 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025). Both are credited in full at the foot of this page.
What a forecast cannot promise
Out to two days accuracy is high; by day seven the trend matters more than the exact figure. For Round Lake the model publishes no rain probability, so the expectation column is our reading.
Severe weather warnings
This page is informational. For official warnings of storms, gales or flooding affecting Round Lake, go to your national weather service through the World Meteorological Organization warning portal.
Understanding the weather and climate of Round Lake
Is this week in Round Lake above or below the October normal?
The average of the next 7 days in Round Lake works out at 54 °F, against a normal of 51 °F for October over 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025). That is 35 °F above typical — a small gap, the size the atmosphere wanders from one week to the next.
Within the week the highest maximum lands on Thu 22/10 (69 °F) and the lowest minimum on Sat 17/10 (39 °F). Forecast rain adds up to 0.04 in, roughly 1% of everything Round Lake gets in an average October (3.3 in). The wettest day is Fri 16/10, with 0.04 in.
When is the wettest and the driest month in Round Lake?
On the 25-year Meteorological and Solar Monthly & Annual Climatologies (January 2001 - December 2025) climatology, the wettest month in Round Lake is June, at about 4.8 in, and the driest is January, at 1.7 in. June takes 2.9 times more than January, so rain in Round Lake has a real season even though it never stops altogether. For October, the month you are reading this in, the average is 3.3 in.
What does the dew point say about how Round Lake feels?
Right now in Round Lake the air is at 57 °F with a dew point of 55 °F and relative humidity of 94%. The two sit within a few tenths of each other: the air is all but saturated, which favours fog, dew on the car and laundry that will not dry.
What is the climate of Round Lake like through the year?
The warmest month in Round Lake is July (73 °F on average) and the coldest is January (21 °F), a swing of about 29 °C around an annual mean of 48 °F. A swing above twenty degrees is continental: summer and winter are almost two climates at the same address.
Because Round Lake lies in the northern hemisphere, at 42.35° north, summer falls in June, July and August, in the middle of the calendar.
How far is Round Lake from Chicago?
The nearest large city to Round Lake is Chicago, about 67 km away in a straight line, to the south-east, with 2,664,452 inhabitants. At that distance it is already common for Round Lake and Chicago to have different days, because a front or a squall line takes hours to cross the gap. Being larger, Chicago shows up in more searches, and plenty of people end up reading its forecast assuming it covers Round Lake.
Words on this page
Apparent temperature
The temperature the body actually feels, rather than the one on the thermometer. It combines air temperature with wind, which carries heat away faster, and humidity, which slows the evaporation of sweat. That is why 30 °C in dry air with a breeze is easier than 28 °C in still, muggy air.
Dew point
The temperature air would have to cool to, at constant pressure and moisture, for water to start condensing. The closer the dew point sits to the air temperature, the less room the vapour has and the muggier the day feels.
Millimetre of rain
The depth of water rain would leave on a flat surface with no run-off. One millimetre is one litre per square metre, no matter how large the area measured is.
Standard definition by World Meteorological Organization (WMO) · Millimetre of rain
Relative humidity
How much water vapour the air holds compared with the most it could hold at that temperature, as a percentage. Because that ceiling rises with heat, the same amount of vapour reads high at dawn and low in the afternoon.
Climate normal
The average of a climate element — temperature, rainfall, humidity — computed over a long, standardised period, usually thirty years. It does not predict anything: it says what is typical for that place in that month, and gives you a ruler for calling a week warm or wet.
Standard definition by World Meteorological Organization (WMO) · Climate normal
Forecast model
A program that solves the equations of the atmosphere on a grid of points and steps forward in time from the state observed now. Your city forecast is the model value at the nearest grid point, which is why two neighbouring towns get almost the same numbers.
Standard definition by MET Norway (Meteorologisk institutt) · Forecast model
Model run
The time the model was executed with the latest observations. Every forecast belongs to a run, and runs age: one from six hours ago knows nothing about the shower that started afterwards. It is the first thing to check when two sources disagree.
Standard definition by MET Norway (Meteorologisk institutt) · Model run
Source, model and licence
- Model
- MET Norway, a partir do ECMWF HRES e, na área nórdica, do MEPS
- Model run
- 16/10/2026, 05:21 UTC
- Source
- MET Norway (Meteorologisk institutt) — Locationforecast 2.0 — Based on data from MET Norway. Licence: CC BY 4.0 / NLOD 2.0.
- Month-by-month climate
- NASA POWER — Climatology (MERRA-2, 2001–2020) — The data was obtained from National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project — Climatology API v2. Dados públicos da NASA, citação obrigatória.
- Cities, coordinates and population
- Dados de cidades: GeoNames (CC BY 4.0)
The page fetches fresh data every 30 minutes. Informational content. For severe weather warnings, follow your country’s official weather service and civil protection authority.