Correct

寒 vs 寒冷 vs 冷

/ hán vs hánlěng vs lěng /
Strokes

Definition

寒, 寒冷 and 冷 all are Adjectives, which means “cold”.

Example

寒, 寒冷 and 冷 all indicate "low temperature".
冷 can be used freely; 寒 is mostly used in set phrases; 寒冷 can also be used freely, but is more literary.

In examples ① and ② below, either 冷 or 寒 can be used, but with different styles.

In examples ③ and ④ only 寒 can be used.
1
Jīnnián
今年
de
dōngtiān
冬天
bié
特别
lěng
  
(
hánlěng
寒冷
  
)
  

It's very cold this winter.

2
Zhème
这么
lěng
  
(
hánlěng
寒冷
  
)
de
tiān
天气
  
,
háiyào
还要
chūmén
出门
  
?

Are you going outside in such a cold day?

3
Jǐnguǎn
尽管
shì
shǔjiǔhántiān
数九寒天
  
,
jiā
大家
réngrán
仍然
huan
喜欢
dào
wài
户外
huódòng
活动
  

Everyone likes going out even if it is in harsh winter.

4
Dōngtiān
冬天
yào
zhù
注意
fánghán
防寒
bǎonuǎn
保暖
  
,
miǎn
以免
gǎnmào
感冒
  

Pay attention to keep warm in winter in case of catching.

寒, 寒冷 and 冷 all indicate "low or cold, indifferent attitude".
Usually, 冷冷 (coldly), 冷下来 (becomes cold), 不冷不热 (neither cold nor hot), 心灰意冷 (be disheartened), etc. are used.

寒 is seldom used by itself, but can be used in phrases 寒心 (be bitterly disappointed), 寒了心 (was bitterly disappointed) meaning disappointed.

冷 also means "rare, quiet, not well-received, etc", but it is usually a part of a word, for example, 冷僻 (deserted), 冷清 (desolate), 冷货 (dull goods), etc.
5
duì
xiǎowáng
小王
zhí
一直
shì
lěnglěng
冷冷
de
  

She is cold to Xiao Wang all the time.

6
Tīngdào
听到
mǎi
de
piào
股票
diē
le
bàn
一半
  
,
xiǎowáng
小王
de
xīnli
心里
xiàzi
下子
jiù
liáng
le
bànjié
半截
  

Hearing that the stock he bought fell by half, Xiao Wang's heart suddenly became half cold.

7
duì
xiǎowáng
小王
jiǎnzhí
简直
shì
lěngruòbīngshuāng
冷若冰霜
  
,
xiǎowáng
小王
zhǐnéng
只能
zhīnánértuì
知难而退
  

She is very cold to Xiao Wang and he has no choice but to give up.

8
Xiǎowáng
小王
de
qíng
热情
zhújiàn
逐渐
lěng
xiàlai
下来
le
  

Xiao Wang's passion is fading.

9
Zhè
shì
zhēn
ràng
xiǎowáng
小王
hánxīn
寒心
  

This made Xiao Wang upset.

冷 also means "rare, quiet, not well-received, etc", but it is usually a part of a word, for example, 冷僻 (deserted), 冷清 (desolate), 冷货 (dull goods), etc.
10
Zhège
这个
dōngtiān
冬天
de
tiān
天气
cháng
异常
hánlěng
寒冷
  
,
shēng
生意
hěn
lěngqīng
冷清
  

The weather this winter was unusually cold and business was deserted.

11
Zhè
shì
lěng
冷僻
de
fāng
地方
  
,
jìn
附近
méiyǒu
没有
duōshǎo
多少
rén
  

It's a lonely place and there aren't many people around.