Partly Cloudy vs Partly Sunny: Difference and Comparison

At the expense of sounding like a nursery rhyme, partly cloudy and partly sunny are terms used in reference to the weather.

It is to be noted that while weather refers to a brief period, climate refers to long-term atmospheric conditions. Cloudy and sunny are two distinct and varying weather conditions.

Key Takeaways

1. Partly cloudy refers to nighttime weather conditions with partial cloud coverage, while partly sunny describes daytime conditions with some sunlight.
2. Both terms indicate a mix of clouds and a clear sky, but partly sunny implies a higher percentage of sunlight.
3. Meteorologists use these terms interchangeably to convey that the sky is neither completely clear nor overcast.

Partly Cloudy vs Partly Sunny

“Partly cloudy” and “partly sunny” refer to the same amount of cloud coverage but from different perspectives. “Partly cloudy” is used when the sky is mostly clear with some clouds present. “Partly sunny” is used when the sky is mostly cloudy with some clear areas.

Partly cloudy is a pretty self-explanatory phrase. This term is used in reference to the weather when the sky is filled less or halfway through with clouds.

A climate jargon, the term, “partly cloudy” can be read while looking up weather forecasts. Predominantly used to describe the condition of the weather during evenings and nights.

Partly sunny means exactly what it sounds like. You look up at the sky and find it partially sunny. The sun’s playing peek-a-boo with you, but not in an irritating way.

Unlike its counterpart, partly sunny can only be used to describe the weather during daylight hours. Once again, used in the weathering field, partly sunny is a common term used to describe an everyday weather phenomenon.

Comparison Table

Parameters of Comparison	Partly Cloudy	Partly Sunny
Definition	Less than halfway cloudy sky; partially filled with clouds.	A pleasant sunny sky; visible sun.
Time	Mostly used to denote evening or night weather.	Used majorly in daytime context.
Statistics	Clouds cover between 3/8 and 5/8 portions of the sky.	The sun covers between 3/8 and 5/8 portions of the sky.
Humidity	Comparatively higher humidity.	Fewer conditions of humidity.
Forecast	Used when rain is expected later.	Used after rains and the sky’s clearing up.

What is Partly Cloudy?

Partly cloudy is a common weather-speak term for when the sky is less than halfway through, partially filled, or covered with clouds.

This is a standard phrase that is used to describe climatic conditions on weather reports, news, research studies, etc.

The term by itself strictly refers to an event where the sky is covered somewhere between 3/8th to 5/8th portions with clouds. 

Although, according to weather experts, the phrases “partly cloudy” and “partly sunny” mean the same thing, there exist subtle differences between the usage of the two.

For instance, partly cloudy is majorly used in referring to or addressing weather conditions during the latter half of the day, more accurately, the evenings and the nights.

This is due to the wording used in the phrase that specifically attributes to the sky being filled with clouds.

Alternate terms such as considerable cloudiness or a cloudy sky are used with reference to the same weather condition.

A cloudy sky is a prerequisite to rain, therefore, a partly cloudy weather situation is used to signify a weather report where it is currently cloudy and one could expect rains in the near future.

As a result of this, partly cloudy also shows high humidity content due to the upcoming downpour.

What is Partly Sunny?

Picked from the rhyme ‘Rain, Rain, Go Away,’ partly sunny might be the perfect weather phenomenon that Litlle Johnny would have loved to play in.

Denoting a beautiful, pleasant sunny day, with the right amount of beautiful golden rays streaking across your skin, a partly sunny day is said so when the sky above sports lovely white clouds and a yellow winking sun.

Yet, another climate jargon, partly sunny, describes weather conditions with the sun covering between 3/8 and 5/8 portions of the big blue sky above us.

Partly sunny can only be used to mention the weather during the daytime. This reduces its usage by a severe limit.

It should be noted that while partly sunny and cloudy can be used in the same context, their usage time varies accordingly. Similar phrases include a mix of clouds and sun, which is used as an alternative.

A partly sunny day is prone to lesser humidity. The term partly sunny speaks for itself and is therefore preferred to be used frequently to share jubilant and bright days at the start of summer or its nostalgic end.

Partly sunny is also used when the downfall of rain is ending and the skies are clearing up.

Main Differences Between Partly Cloudy and Partly Sunny

1. A partly cloudy sky is filled with clouds in a set proportion. A partly sunny sky can be seen when there’s a gentle presence of the sun.
2. A partly cloudy sky has a cloud cover ranging from 3/8 and 5/8 portions of the sky, whereas a partly sunny has 3/8 to 5/8 of the sky covered by the sun.
3. Cloudy weather has a higher content of humidity. Sunny weather has a comparatively lower humidity level.
4. The phrases partly cloudy and sunny are predominantly used during night and day.
5. They’re both weather phenomena that are used to denote the before and after rain situations, with partly cloudy referring to the former and partly sunny meaning the latter.

References

1. https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/WR018i004p00931
2. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1559-1816.1996.tb01842.x

Last Updated : 24 June, 2023